Section 1.4

Graphical Representation of Functions

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Problem 237

Draw the graphs of the linear homogeneous function

y=ax y=ax

for a=0,12,1,2,−1a=0,\dfrac {1}{2},1,2,-1.

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Problem 238

Draw the graphs of the linear function

y=x+b y=x+b

for b=0,1,2,−1b=0,1,2,-1.

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Problem 239

Draw the graphs of the linear functions:

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(a)

y=2x+3y=2x+3;

(b)

y=2−0.1xy=2-0.1x;

(c)

y=−x2−1y=-\dfrac {x}{2}-1.

Problem 240

The coefficient of linear expansion of iron is a=1.2×10−6a=1.2 \times 10^{-6}. On a suitable scale, plot the graph of the function

l=f(T)(−40∘≤T≤100∘) l=f(T) \quad (-40^{\circ } \leq T \leq 100^{\circ })

where TT denotes the temperature (in degrees) and ll denotes the length of the iron rod at temperature TT. Assume that when T=0∘T=0^{\circ }, l=100l=100 cm.

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Problem 241

Two particles move on a number axis. The first particle, at time t=0t=0, is at a point 20 meters to the left of the origin, with velocity v1=10v_{1}=10 m/s; the second particle, at t=0t=0, is at a point 30 meters to the right of the origin OO, with velocity v2=−20v_{2}=-20 m/s. Plot the graphs of the equations of motion of the two points and find the time and position at which they meet.

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Problem 242

Plot the graphs of the quadratic rational integral function (parabola):

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(a)

y=ax2y=ax^{2}, for a=1,12,2,−1a=1, \dfrac {1}{2}, 2, -1;

(b)

y=(x−x0)2y=(x-x_{0})^{2}, for x0=0,1,2,−1x_{0}=0, 1, 2, -1;

(c)

y=x2+cy=x^{2}+c, for c=0,1,2,−1c=0, 1, 2, -1.

Problem 243

Convert the quadratic trinomial

y=ax2+bx+c y=ax^{2}+bx+c

into the form

y=y0+a(x−x0)2, y=y_{0}+a(x-x_{0})^{2},

plot its graph, and study the examples:

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(a)

y=8x−2x2y=8x-2x^{2};

(b)

y=x2+3x+2y=x^{2}+3x+2;

(c)

y=−x2+2x−1y=-x^{2}+2x-1;

(d)

y=12x2+x+1y=\dfrac {1}{2}x^{2}+x+1.

Problem 244

A particle is launched with initial velocity v0=600v_{0}=600 meters per second in a direction making angle α=45∘\alpha =45^{\circ } with the horizontal plane. Plot the graph of the trajectory, and find the maximum height and the range of the flight (assume g≈10g \approx 10 m/s2{}^{2}, air resistance neglected).

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Problem 245

Plot the graph of the rational integral function of degree higher than two: y=x3+1y=x^{3}+1.

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Problem 246

Plot the graph of the rational integral function of degree higher than two: y=(1−x2)(2+x)y=(1-x^{2})(2+x).

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Problem 247

Plot the graph of the rational integral function of degree higher than two: y=x2−x4y=x^{2}-x^{4}.

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Problem 248

Plot the graph of the rational integral function of degree higher than two: y=x(a−x)2(a+x)3(a>0)y=x(a-x)^{2}(a+x)^{3} \quad (a>0).

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Problem 249

Plot the graph of the linear fractional function (hyperbola): y=1xy=\dfrac {1}{x}.

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Problem 250

Plot the graph of the linear fractional function (hyperbola): y=1−x1+xy=\dfrac {1-x}{1+x}.

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Problem 251

Convert the linear fractional function

y=ax+bcx+d(ad−bc≠0,c≠0) y=\frac{ax+b}{cx+d} \quad (ad-bc \neq 0, c \neq 0)

into the form

y=y0+mx−x0. y=y_{0}+\frac{m}{x-x_{0}} .

Then plot its graph. Study the example

y=3x+22x−3. y=\frac{3x+2}{2x-3} .
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Problem 252

A gas at pressure p0=1p_{0}=1 atmosphere occupies volume v0=12v_{0}=12 cubic meters. Assuming the temperature of the gas remains constant, plot the graph of the gas volume vv as a function of the pressure (Boyle--Mariotte law).

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Problem 253

Plot the graph of the following rational fractional function: y=x+1xy=x+\dfrac {1}{x} (hyperbola).

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Problem 254

Plot the graph of the following rational fractional function: y=x2+1xy=x^{2}+\dfrac {1}{x} (Newton's cubic curve).

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Problem 255

Plot the graph of the following rational fractional function: y=x+1x2y=x+\dfrac {1}{x^{2}}.

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Problem 256

Graph the following rational fractional function: y=11+x2y=\dfrac {1}{1+x^{2}} (the witch of Agnesi).

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Problem 257

Graph the following rational fractional function: y=2x1+x2y=\dfrac {2x}{1+x^{2}} (the serpentine of Newton).

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Problem 258

Graph the following rational fractional function: y=11−x2y=\dfrac {1}{1-x^{2}}.

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Problem 259

Graph the following rational fractional function: y=x1−x2y=\dfrac {x}{1-x^{2}}.

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Problem 260

Graph the following rational fractional function: y=11+x−2x+11−xy=\dfrac {1}{1+x}-\dfrac {2}{x}+\dfrac {1}{1-x}.

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Problem 261

Graph the following rational fractional function: y=11+x−2x2+11−xy=\dfrac {1}{1+x}-\dfrac {2}{x^{2}}+\dfrac {1}{1-x}.

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Problem 262

Graph the following rational fractional function: y=(x+1)(x−2)(x−1)(x+2)y=\dfrac {(x+1)(x-2)}{(x-1)(x+2)}.

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Problem 263

Reduce the function

y=ax2+bx+ca1x+b1(a1≠0) y=\frac{ax^{2}+bx+c}{a_{1}x+b_{1}} \quad (a_{1} \neq 0)

to the form

y=kx+m+nx−x0, y=kx+m+\frac{n}{x-x_{0}},

and then sketch its graph. Study the example

y=x2−4x+3x+1. y=\frac{x^{2}-4x+3}{x+1} .
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Problem 264

A particle is at distance xx from a center of gravitational attraction. Given that the force of attraction is F=10F=10 kg when x=1x=1 meter, graph the absolute value of the force of attraction FF on the particle (Newton's law).

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Problem 265

According to the van der Waals law (Закон Ван-дер-Ваальса), at constant temperature the volume vv of a real gas and its pressure pp are related by

(p+av2)(v−b)=c \left(p+\frac{a}{v^{2}}\right)(v-b)=c

Given a=2,b=0.1a=2, b=0.1 and c=10c=10, graph the function p=p(v)p=p(v).

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Problem 266

Graph the following irrational function: y=±−x−2y=\pm \sqrt{-x-2} (a parabola).

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Problem 267

Graph the following irrational function: y=±xxy=\pm x\sqrt{x} (a semicubical parabola).

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Problem 268

Graph the following irrational function: y=±12100−x2y=\pm \dfrac {1}{2}\sqrt{100-x^{2}} (an ellipse).

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Problem 269

Graph the following irrational function: y=±x2−1y=\pm \sqrt{x^{2}-1} (a hyperbola).

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Problem 270

Graph the following irrational function: y=±1−x1+xy=\pm \sqrt{\dfrac {1-x}{1+x}}.

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Problem 271

Graph the following irrational function: y=±x100−x2y=\pm x\sqrt{100-x^{2}}.

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Problem 272

Graph the following irrational function: y=±xx10−xy=\pm x\sqrt{\dfrac {x}{10-x}} (the cissoid).

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Problem 273

Graph the following irrational function: y=±(x2−1)(9−x2)y=\pm \sqrt{(x^{2}-1)(9-x^{2})}.

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Problem 274

Graph the power function

y=xn y=x^{n}

for: (a) n=1,3,5n=1,3,5; (b) n=2,4,6n=2,4,6.

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(a)
(b)
Problem 275

Graph the power function

y=xn y=x^{n}

for: (a) n=−1,−3n=-1,-3; (b) n=−2,−4n=-2,-4.

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(a)
(b)
Problem 276

Graph the radical

y=xm y=\sqrt[m]{x}

for: (a) m=2,4m=2,4; (b) m=3,5m=3,5.

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(a)
(b)
Problem 277

Let:

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(a)

m=2,k=1m=2, k=1;

(b)

m=2,k=3m=2, k=3;

(c)

m=3,k=1m=3, k=1;

(d)

m=3,k=2m=3, k=2;

(e)

m=3,k=4m=3, k=4;

(f)

m=4,k=2m=4, k=2;

(g)

m=4,k=3m=4, k=3.

Plot the graph of the radical

y=xkm. y=\sqrt[m]{x^{k}} .
Problem 278

Plot the exponential function

y=ax y=a^{x}

for a=12,1,2,e,10a=\dfrac {1}{2}, 1, 2, e, 10.

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Problem 279

Plot the graph of the composite exponential function

y=ey1 y=e^{y_{1}}

where:

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(a)

y1=x2y_{1}=x^{2};

(b)

y1=−x2y_{1}=-x^{2};

(c)

y1=1xy_{1}=\dfrac {1}{x};

(d)

y1=1x2y_{1}=\dfrac {1}{x^{2}};

(e)

y1=−1x2y_{1}=-\dfrac {1}{x^{2}};

(f)

y1=2x1−x2y_{1}=\dfrac {2x}{1-x^{2}}.

Problem 280

Plot the graph of the logarithmic function y=log⁡axy=\log_{a}x for a=12,2,e,10a=\dfrac {1}{2}, 2, e, 10.

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Problem 281

Plot the graphs of the following functions:

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(a)

y=ln⁡(−x)y=\ln (-x);

(b)

y=−ln⁡xy=-\ln x.

Problem 282

Let:

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(a)

y1=1+x2y_{1}=1+x^{2};

(b)

y1=(x−1)(x−2)2(x−3)3y_{1}=(x-1)(x-2)^{2}(x-3)^{3};

(c)

y1=1−x1+xy_{1}=\dfrac {1-x}{1+x};

(d)

y1=1x2y_{1}=\dfrac {1}{x^{2}};

(e)

y1=1+exy_{1}=1+e^{x}.

Plot the graph of the composite logarithmic function y=ln⁡y1y=\ln y_{1}.

Problem 283

Plot the graph of the function

y=log⁡x2 y=\log _{x}2
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Problem 284

Plot the graph of the function

y=Asin⁡x y=A\sin x

for A=1,10,−2A=1, 10, -2.

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Problem 285

Plot the graph of the function

y=sin⁡(x−x0) y=\sin (x-x_{0})

for x0=0,π4,π2,3π4,πx_{0}=0, \dfrac {\pi }{4}, \dfrac {\pi }{2}, \dfrac {3\pi }{4}, \pi.

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Problem 286

Plot the graph of the function

y=sin⁡nx y=\sin nx

Let n=1,2,3,12,13n=1, 2, 3, \dfrac {1}{2}, \dfrac {1}{3}.

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Problem 287

Convert the function

y=acos⁡x+bsin⁡x y=a\cos x+b\sin x

into the form

y=Asin⁡(x−x0), y=A\sin (x-x_{0}),

and then plot its graph.

Study the example

y=6cos⁡x+8sin⁡x. y=6\cos x+8\sin x.
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Problem 288

Plot the graph of the following trigonometric function: y=cos⁡xy=\cos x.

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Problem 289

Plot the graph of the following trigonometric function: y=tg⁡xy=\tg x.

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Problem 290

Plot the graph of the following trigonometric function: y=ctg⁡xy=\ctg x.

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Problem 291

Plot the graph of the following trigonometric function: y=sec⁡xy=\sec x.

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Problem 292

Plot the graph of the following trigonometric function: y=csc⁡xy=\csc x.

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Problem 293

Plot the graph of the following trigonometric function: y=sin⁡2xy=\sin^{2}x.

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Problem 294

Plot the graph of the following trigonometric function: y=sin⁡3xy=\sin^{3}x.

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Problem 295

Plot the graph of the following trigonometric function: y=ctg⁡2xy=\ctg^{2}x.

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Problem 296

Plot the graph of the function: y=sin⁡x⋅sin⁡3xy=\sin x \cdot \sin 3x.

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Problem 297

Plot the graph of the function: y=±cos⁡xy=\pm \sqrt{\cos x}.

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Problem 298

Plot the graph of the following function: y=sin⁡x2y=\sin x^{2}.

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Problem 299

Plot the graph of the following function: y=sin⁡1xy=\sin \dfrac {1}{x}.

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Problem 300

Plot the graph of the following function: y=xcos⁡πxy=x\cos \dfrac {\pi }{x}.

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Problem 300.1
[NO TASK]
Problem 301

Plot the graph of the following function: y=tg⁡πxy=\tg \dfrac {\pi }{x}.

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Problem 301.1
[NO TASK]
Problem 302

Plot the graph of the following function: y=x(2+sin⁡1x)y=x\left(2+\sin \dfrac {1}{x}\right).

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Problem 303

Plot the graph of the following function: y=±1−x2sin⁡πxy=\pm \sqrt{1-x^{2}}\sin \dfrac {\pi }{x}.

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Problem 304

Plot the graph of the following function: y=sin⁡xxy=\dfrac {\sin x}{x}.

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Problem 305

Plot the graph of the following function: y=excos⁡xy=e^{x}\cos x.

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Problem 306

Plot the graph of the following function: y=±2−xsin⁡πxy=\pm 2^{-x}\sqrt{\sin \pi x}.

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Problem 307

Graph the following function: y=cos⁡x1+x2y=\dfrac {\cos x}{1+x^{2}}.

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Problem 308

Graph the following function: y=ln⁡(cos⁡x)y=\ln (\cos x).

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Problem 309

Graph the following function: y=cos⁡(ln⁡x)y=\cos (\ln x).

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Problem 310

Graph the following function: y=e1sin⁡xy=e^{\frac{1}{\sin x}}.

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Problem 311

Graph the following inverse trigonometric function: y=arcsin⁡xy=\arcsin x.

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Problem 312

Graph the following inverse trigonometric function: y=arccos⁡xy=\arccos x.

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Problem 313

Graph the following inverse trigonometric function: y=arctg⁡xy=\arctg x.

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Problem 314

Graph the following inverse trigonometric function: y=arcctg⁡xy=\arcctg x.

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Problem 315

Graph the following inverse trigonometric function: y=arcsin⁡1xy=\arcsin \dfrac {1}{x}.

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Problem 316

Graph the following inverse trigonometric function: y=arccos⁡1xy=\arccos \dfrac {1}{x}.

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Problem 317

Graph the following inverse trigonometric function: y=arctg⁡1xy=\arctg \dfrac {1}{x}.

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Problem 318

Graph the following inverse trigonometric function: y=arcsin⁡(sin⁡x)y=\arcsin (\sin x).

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Problem 319

Graph the following inverse trigonometric function: y=arcsin⁡(cos⁡x)y=\arcsin (\cos x).

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Problem 320

Graph the following inverse trigonometric function: y=arccos⁡(cos⁡x)y=\arccos (\cos x).

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Problem 321

Graph the following inverse trigonometric function: y=arctg⁡(tg⁡x)y=\arctg (\tg x).

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Problem 322

Graph the following inverse trigonometric function: y=arcsin⁡(2sin⁡x)y=\arcsin (2\sin x).

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Problem 323

Let

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(a)

y1=1−x2y_{1}=1-\dfrac {x}{2};

(b)

y1=2x1+x2y_{1}=\dfrac {2x}{1+x^{2}};

(c)

y1=1−x1+xy_{1}=\dfrac {1-x}{1+x};

(d)

y1=exy_{1}=e^{x}.

Construct the graph of the function

y=arcsin⁡y1 y=\arcsin y_{1}
Problem 324

Let

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(a)
(b)

y1=1x2y_{1}=\dfrac {1}{x^{2}};

(c)

y1=ln⁡xy_{1}=\ln x;

(d)

y1=1sin⁡xy_{1}=\dfrac {1}{\sin x}.

Construct the graph of the function

y=arctg⁡y1 y=\arctg y_{1}
Problem 324.1

y1=x2y_{1}=x^{2};

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(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
(l)
Problem 325

Given the graph of the function y=f(x)y=f(x), construct the graphs of the following functions

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(a)

y=−f(x)y=-f(x);

(b)

y=f(−x)y=f(-x);

(c)

y=−f(−x)y=-f(-x).

Problem 326

Given the graph of the function y=f(x)y=f(x), construct the graphs of the following functions:

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(a)
(b)

y=y0+f(x−x0)y=y_{0}+f(x-x_{0});

(c)

y=f(2x)y=f(2x);

(d)

y=f(kx+b)y=f(kx+b) (k≠0k \neq 0).

Problem 326.1

y=f(x−x0)y=f(x-x_{0});

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Problem 327

Construct the graphs of the functions

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(a)

y=2+1−xy=2+\sqrt{1-x};

(b)

y=1−e−xy=1-e^{-x};

(c)

y=ln⁡(1+x)y=\ln (1+x);

(d)

y=−π2arcsin⁡(1+x)y=-\dfrac {\pi }{2}\arcsin (1+x);

(e)

y=3+2cos⁡3xy=3+2\cos 3x.

Problem 328

Given the graph of the function y=f(x)y=f(x), construct the graphs of the following functions:

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(a)

y=∣f(x)∣y=\left|f(x)\right|;

(b)

y=12[∣f(x)∣+f(x)]y=\dfrac {1}{2}[\left|f(x)\right|+f(x)];

(c)

y=12[∣f(x)∣−f(x)]y=\dfrac {1}{2}[\left|f(x)\right|-f(x)].

Problem 329

Given the graph of the function y=f(x)y=f(x), construct the graphs of the following functions:

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(a)
(b)
(c)

y=ln⁡f(x)y=\ln f(x);

(d)

y=f[f(x)]y=f[f(x)];

(e)

y=sgn⁡f(x)y=\operatorname {sgn}f(x);

(f)

y=[f(x)]y=[f(x)].

Problem 329.1

y=f2(x)y=f^{2}(x);

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(a)
(b)
(c)
(d)
(e)
(f)
(g)
Problem 329.2

y=f(x)y=\sqrt{f(x)};

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(a)
(b)
(c)
(d)
(e)
Problem 330

Given the graphs of the functions y=f(x)y=f(x) and y=g(x)y=g(x), construct the graphs of the following functions:

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(a)

y=f(x)+g(x)y=f(x)+g(x);

(b)

y=f(x)g(x)y=f(x)g(x);

(c)

y=f[g(x)]y=f[g(x)].

Problem 331

Using graphical addition, construct the graph of the function: y=1+x+exy=1+x+e^{x}.

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Problem 332

Using graphical addition, construct the graph of the function: y=(x+1)−2+(x−1)−2y=(x+1)^{-2}+(x-1)^{-2}.

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Problem 333

Using graphical addition, sketch the graph of the following function:y=x+sin⁡xy=x+\sin x.

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Problem 334

Using graphical addition, sketch the graph of the following function:y=x+arctg⁡xy=x+\operatorname {arctg}x.

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Problem 335

Using graphical addition, sketch the graph of the following function:y=cos⁡x+12cos⁡2x+13cos⁡3xy=\cos x+\dfrac {1}{2}\cos 2x+\dfrac {1}{3}\cos 3x.

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Problem 336

Using graphical addition, sketch the graphs of the following functions: y=sin⁡x−13sin⁡3x+15sin⁡5xy=\sin x-\dfrac {1}{3}\sin 3x+\dfrac {1}{5}\sin 5x.

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Problem 337

Using graphical addition, sketch the graph of the following function:y=sin⁡4x+cos⁡4xy=\sin^{4}x+\cos^{4}x.

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Problem 338

Using graphical addition, sketch the graph of the following function:y=∣1−x∣+∣1+x∣y=\left|1-x\right|+\left|1+x\right|.

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Problem 339

Using graphical addition, sketch the graph of the following function:y=∣1−x∣−∣1+x∣y=\left|1-x\right|-\left|1+x\right|.

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Problem 340

Sketch the graphs of the hyperbolic functions:

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(a)

y=ch⁡xy=\operatorname {ch}x, where ch⁡x=12(ex+e−x)\operatorname {ch}x=\dfrac {1}{2}(e^{x}+e^{-x});

(b)

y=sh⁡xy=\operatorname {sh}x, where sh⁡x=12(ex−e−x)\operatorname {sh}x=\dfrac {1}{2}(e^{x}-e^{-x});

(c)

y=th⁡xy=\operatorname {th}x, where th⁡x=sh⁡xch⁡x\operatorname {th}x=\dfrac {\operatorname {sh}x}{\operatorname {ch}x}.

Problem 341

Using graphical multiplication, sketch the graphs of the following functions: y=xsin⁡xy=x\sin x.

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Problem 342

Using graphical multiplication, sketch the graphs of the following functions: y=xcos⁡xy=x\cos x.

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Problem 343

Using graphical multiplication, sketch the graphs of the following functions: y=x2sin⁡2xy=x^{2}\sin^{2}x.

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Problem 344

Using graphical multiplication, sketch the graph of the following function:y=sin⁡x1+x2y=\dfrac {\sin x}{1+x^{2}}.

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Problem 345

Using graphical multiplication, sketch the graph of the following function:y=e−x2cos⁡2xy=e^{-x^{2}}\cos 2x.

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Problem 346

Using graphical multiplication, sketch the graph of the following function:y=xsgn⁡(sin⁡x)y=x\operatorname {sgn}(\sin x).

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Problem 347

Using graphical multiplication, sketch the graph of the following function:y=[x]⋅∣sin⁡πx∣y=[x] \cdot \left|\sin \pi x\right|.

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Problem 348

Using graphical multiplication, sketch the graph of the following function:y=cos⁡x⋅sgn⁡(sin⁡x)y=\cos x \cdot \operatorname {sgn}(\sin x).

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Problem 349

Let

f(x)={1−∣x∣,if∣x∣⩽1;0,if∣x∣>1. f(x)= \begin{cases} 1-\left|x\right|, & \text{if} \left|x\right| \leqslant 1 ; \\ 0, & \text{if} \left|x\right|>1 . \end{cases}

Sketch the graph of the function y=f(x)f(a−x)y=f(x)f(a-x) when (a) a=0a=0, (б) a=1a=1, (в) a=2a=2.

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(a)
(b)
(c)
Problem 350

Sketch the graph of the function y=x+xsgn⁡(sin⁡πx)y=x+\sqrt{x}\operatorname {sgn}(\sin \pi x).

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Problem 351

Sketch the graph of the function y=1f(x)y=\dfrac {1}{f(x)}, where f(x)=x2(1−x2)f(x)=x^{2}(1-x^{2}).

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Problem 352

Sketch the graph of the function y=1f(x)y=\dfrac {1}{f(x)}, where f(x)=x(1−x)2f(x)=x(1-x)^{2}.

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Problem 353

Sketch the graph of the function y=1f(x)y=\dfrac {1}{f(x)}, where f(x)=sin⁡2xf(x)=\sin^{2}x.

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Problem 354

Sketch the graph of the function y=1f(x)y=\dfrac {1}{f(x)}, where f(x)=ln⁡xf(x)=\ln x.

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Problem 355

Sketch the graph of the function y=1f(x)y=\dfrac {1}{f(x)}, where f(x)=exsin⁡xf(x)=e^{x}\sin x.

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Problem 356

Let

f(u)={−1,if −∞<u<−1;u,if −1⩽u⩽1;1,if 1<u<+∞. f(u)= \begin{cases} -1, & \text{if } -\infty <u<-1 ; \\ u, & \text{if } -1 \leqslant u \leqslant 1 ; \\ 1, & \text{if } 1<u<+\infty . \end{cases}

Sketch the graph of the composite function y=f(u)y=f(u), where u=2sin⁡xu=2\sin x.

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Problem 357

Let φ(x)=12(x+∣x∣)\varphi (x)=\dfrac {1}{2}(x+\left|x\right|) and

ψ(x)={x,if x<0;x2,if x⩾0. \psi (x)= \begin{cases} x, & \text{if } x<0 ; \\ x^{2}, & \text{if } x \geqslant 0 . \end{cases}

Sketch the graphs of the following functions:

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(a)

y=φ[φ(x)]y=\varphi [\varphi (x)];

(b)

y=φ[ψ(x)]y=\varphi [\psi (x)];

(c)

y=ψ[φ(x)]y=\psi [\varphi (x)];

(d)

y=ψ[ψ(x)]y=\psi [\psi (x)].

Problem 358

Let

φ(x)={1,if ∣x∣⩽1;0,if ∣x∣>1. \varphi (x)= \begin{cases} 1, & \text{if } \left|x\right| \leqslant 1 ; \\ 0, & \text{if } \left|x\right|>1 . \end{cases}

and

ψ(x)={2−x2,if ∣x∣⩽2;2,if ∣x∣>2. \psi (x)= \begin{cases} 2-x^{2}, & \text{if } \left|x\right| \leqslant 2 ; \\ 2, & \text{if } \left|x\right|>2 . \end{cases}

Sketch the graphs of the functions:

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(a)

y=φ[φ(x)]y=\varphi [\varphi (x)];

(b)

y=φ[ψ(x)]y=\varphi [\psi (x)];

(c)

y=ψ[φ(x)]y=\psi [\varphi (x)];

(d)

y=ψ[ψ(x)]y=\psi [\psi (x)]

Problem 359

A function f(x)f(x) is defined on the domain of positive numbers x>0x>0. Extend f(x)f(x) to the domain of negative numbers x<0x<0 so that the resulting function is: (1) even; (2) odd. Let

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(a)

f(x)=1−xf(x)=1-x;

(b)

f(x)=2x−x2f(x)=2x-x^{2};

(c)

f(x)=xf(x)=\sqrt{x};

(d)

f(x)=sin⁡xf(x)=\sin x;

(e)

f(x)=exf(x)=e^{x};

(f)

f(x)=ln⁡xf(x)=\ln x.

Sketch the graph of each resulting function.

Problem 360

Determine about which vertical axis the graph of each of the following functions is symmetric:

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(a)

y=ax2+bx+cy=ax^{2}+bx+c;

(b)

y=1x2+1(1−x)2y=\dfrac {1}{x^{2}}+\dfrac {1}{(1-x)^{2}};

(c)

y=a+x+b−xy=\sqrt{a+x}+\sqrt{b-x} (0<a<b0<a<b);

(d)

y=a+bcos⁡xy=a+b\cos x.

Problem 361

Determine the center of symmetry of the graph of each of the following functions:

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(a)

y=ax+by=ax+b;

(b)

y=ax+bcx+dy=\dfrac {ax+b}{cx+d};

(c)

y=ax3+bx2+cx+dy=ax^{3}+bx^{2}+cx+d;

(d)

y=1x−1+1x−2+1x−3y=\dfrac {1}{x-1}+\dfrac {1}{x-2}+\dfrac {1}{x-3};

(e)

y=1+x−23y=1+\sqrt[3]{x-2}.

Problem 362

Sketch the graphs of the periodic functions:

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(a)

y=∣sin⁡x∣y=\left|\sin x\right|;

(b)

y=sgn⁡cos⁡xy=\operatorname {sgn}\cos x;

(c)

y=f(x)y=f(x), where f(x)=Axl(2−xl)f(x)=A\dfrac {x}{l}\left(2-\dfrac {x}{l}\right), given that 0⩽x⩽2l0 \leqslant x \leqslant 2l and f(x+2l)≡f(x)f(x+2l) \equiv f(x);

(d)

y=[x]−2(x2)y=[x]-2\left(\dfrac {x}{2}\right);

(e)

y=(x)y=(x), where (x)(x) denotes the distance from the number xx to the nearest integer.

Problem 363

Prove: if the graph of the function y=f(x)y=f(x) (−∞<x<+∞-\infty <x<+\infty) is symmetric with respect to the two vertical lines x=ax=a and x=bx=b (b>ab>a), then the function f(x)f(x) is periodic.

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Problem 364

Prove: if the graph of the function y=f(x)y=f(x) (−∞<x<+∞-\infty <x<+\infty) is symmetric with respect to the two points A(a,y0)A(a,y_{0}) and B(b,y1)B(b,y_{1}) (b>ab>a), then the function f(x)f(x) is the sum of a linear function and a periodic function. In particular, if y0=y1y_{0}=y_{1}, then f(x)f(x) is a periodic function.

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Problem 365

Prove: if the graph of the function y=f(x)y=f(x) (−∞<x<+∞-\infty <x<+\infty) is symmetric with respect to the point A(a,y0)A(a,y_{0}) and the line x=bx=b (b≠ab \neq a), then the function f(x)f(x) is periodic.

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Problem 366

Given f(x+1)=2f(x)f(x+1)=2f(x) and, for 0⩽x⩽10 \leqslant x \leqslant 1, f(x)=x(1−x)f(x)=x(1-x), sketch the graph of the function

y=f(x)(−∞<x<+∞) y=f(x) \quad (-\infty <x<+\infty )
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Problem 367

Given f(x+π)=f(x)+sin⁡xf(x+\pi )=f(x)+\sin x, and for 0⩽x⩽π0 \leqslant x \leqslant \pi, f(x)=0f(x)=0, sketch the graph of the function

y=f(x)(−∞<x<+∞) y=f(x) \quad (-\infty <x<+\infty )
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Problem 368

Sketch the graph of the function y=y(x)y=y(x), given:

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(a)

x=y−y3x=y-y^{3};

(b)

x=1−y1+y2x=\dfrac {1-y}{1+y^{2}};

(c)

x=y−ln⁡yx=y-\ln y;

(d)

x2=sin⁡yx^{2}=\sin y.

Problem 369

Sketch the graphs of the following functions given in parametric form:

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(a)

x=1−tx=1-t, y=1−t2y=1-t^{2};

(b)

x=t+1tx=t+\dfrac {1}{t}, y=t+1t2y=t+\dfrac {1}{t^{2}};

(c)

x=10cos⁡tx=10\cos t, y=sin⁡ty=\sin t (ellipse);

(d)

x=ch⁡tx=\operatorname {ch}t, y=sh⁡ty=\operatorname {sh}t (hyperbola);

(e)

x=5cos⁡2tx=5\cos^{2}t, y=3sin⁡2ty=3\sin^{2}t;

(f)

x=2(t−sin⁡t)x=2(t-\sin t), y=2(1−cos⁡t)y=2(1-\cos t) (cycloid);

(g)

x=tt+ttx=t^{t+\sqrt[t]{t}}, y=t+1ty=\sqrt[t]{t+1} (t>0t>0).

Problem 370

Draw the graphs of the following implicit functions:

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(a)
(b)

x3+y3−xy=0x^{3}+y^{3}-xy=0 (the folium of Descartes);

(c)

x+y=1\sqrt{x}+\sqrt{y}=1 (a parabola);

(d)

x23+y23=4x^{\frac{2}{3}}+y^{\frac{2}{3}}=4 (an astroid);

(e)

sin⁡x=sin⁡y\sin x=\sin y;

(f)

cos⁡(πx2)=cos⁡(πy)\cos (\pi x^{2})=\cos (\pi y);

(g)

xy=yxx^{y}=y^{x} (x>0,y>0x>0,y>0);

(h)

x−∣x∣=y−∣y∣x-\left|x\right|=y-\left|y\right|.

Problem 370.1

x2−xy+y2=1x^{2}-xy+y^{2}=1 (an ellipse);

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(a)
(b)
(c)
(d)
Problem 371

In the polar coordinate system (r,φ)(r,\varphi ), draw the graph of the function r=r(φ)r=r(\varphi ). Let:

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(a)
(b)
(c)

r=φφ+1r=\dfrac {\varphi }{\varphi +1} (0⩽φ<+∞0 \leqslant \varphi <+\infty);

(d)

r=2φ2πr=2^{\frac{\varphi }{2\pi }} (the logarithmic spiral);

(e)

r=2(1+cos⁡φ)r=2(1+\cos \varphi ) (a cardioid);

(f)

r=10sin⁡3φr=10\sin 3\varphi (a three-petaled rose);

(g)

r2=36cos⁡2φr^{2}=36\cos 2\varphi (the lemniscate of Bernoulli);

(h)

φ=rr−1\varphi =\dfrac {r}{r-1} (r>1r>1);

(i)

φ=2πsin⁡r\varphi =2\pi \sin r.

Problem 371.1

r=φr=\varphi (the spiral of Archimedes);

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(a)
(b)
(c)
Problem 371.2

r=πφr=\dfrac {\pi }{\varphi } (the hyperbolic spiral);

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(a)
(b)
Problem 372

Draw the graph of the function y=x3−3x+1y=x^{3}-3x+1 in order to find approximate solutions of the equation x3−3x+1=0x^{3}-3x+1=0.

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Problem 373

Use the graphical method to solve the following equation: x3−4x−1=0x^{3}-4x-1=0.

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Problem 374

Use the graphical method to solve the following equation: x4−4x+1=0x^{4}-4x+1=0.

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Problem 375

Use the graphical method to solve the following equation: x=2−xx=2^{-x}.

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Problem 376

Use the graphical method to solve the following equation: lg⁡x=0.1x\lg x=0.1x.

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Problem 377

Use the graphical method to solve the following equation: 10x=x210^{x}=x^{2}.

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Problem 378

Use the graphical method to solve the following equation: tg⁡x=x\operatorname {tg}x=x (0⩽x⩽2π0 \leqslant x \leqslant 2\pi).

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Problem 379

Use the graphical method to solve the following system of equations: x+y2=1x+y^{2}=1, 16x2+y=416x^{2}+y=4.

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Problem 380

Solve the following system of equations graphically: x2+y2=100x^{2}+y^{2}=100, y=10(x2−x−2)y=10(x^{2}-x-2).

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