Section 1.8

Foci and Directrices

[18/94%]
Show
LaTeX
Problem 319

Find the focus and directrix of the parabola

x2−2xy+y2−6x−2y+9=0. x^{2}-2xy+y^{2}-6x-2y+9=0.
?
Problem 320

Find the foci and directrices of the curve

3x2−4xy−2x+4y−5=0. 3x^{2}-4xy-2x+4y-5=0.
?
Problem 321

Find the foci and directrices of the curve

8x2+4xy+5y2+8x−16y−16=0. 8x^{2}+4xy+5y^{2}+8x-16y-16=0.
?
Problem 322

A second-order curve passes through the origin, its focus is at the point (−1,1)(-1,1), and the corresponding directrix has the equation x+y−2=0x+y-2=0. Find the curve.

?
Problem 323

Find the ellipse passing through the point (4,2)(4,2) and having foci at the points (4,3)(4,3) and (0,−1)(0,-1).

?
Problem 324

Find the ellipse with foci at the points (1,2)(1,2), (2,1)(2,1), passing through the point (5,5)(5,5).

?
Problem 325

Find the equilateral hyperbola from its directrix x+y−1=0x+y-1=0 and focus (1,1)(1,1).

?
Problem 326

Find the parabola from its points (1,1)(1,1), (1,2)(1,2) and its directrix x+y−1=0x+y-1=0.

?
Problem 327

A second-order curve passes through the point (0,−1)(0,-1), has center (1,1)(1,1), and has as directrix the line x+2y+1=0x+2y+1=0. Find the curve.

?
Problem 328

Find the second-order curve from its points (0,1)(0,1), (1,0)(1,0), (0,2)(0,2) and focus (1,1)(1,1).

?
Problem 329

Find the second-order curve from its directrix x+y+1=0x+y+1=0, axis y=xy=x, and points (0,0)(0,0) and (1,0)(1,0).

?
Problem 330

Find the second-order curve from its points (4,5)(4,5), (−3,4)(-3,4), focus (1,1)(1,1), and axis of symmetry x+y−2=0x+y-2=0.

?
Problem 331

Find the parabola from its vertex (0,0)(0,0) and focus (1,1)(1,1).

?
Problem 332

Find the hyperbola from its asymptotes x+y−1=0x+y-1=0, x−y+1=0x-y+1=0 and focus (0,2)(0,2).

?
Problem 333

Find the locus of the foci of parabolas passing through the point (1,−1)(1,-1) and having as directrix the line x+y+1=0x+y+1=0.

?
Problem 334

Find the locus of the vertices of parabolas passing through a given point and having a given directrix.

?
Problem 335

Find the locus of the centers of equilateral hyperbolas passing through the point (0,0)(0,0) and having as directrix the line x+y+1=0x+y+1=0.

?
Problem 336

What is the locus of the foci of second-order curves inscribed in a given parallelogram?

?