Increment of the argument along a curve
[15/80%]Let be the analytic function defined in the disk so that in and is positive for . An analytic function in is obtained from by analytic continuation along the path starting and ending at (see Fig. 5.2). Express in terms of .
Trace how the argument of the quantity changes as traces, counterclockwise, a closed curve enclosing the points and .
Study how the arguments of the quantities , , and change as traces the same contour as in problem 2480 (a closed curve traversed counterclockwise and enclosing the points and ).
How does the function change, for real and , if traces a closed contour going counterclockwise around the points and ?
The same question for the function and a contour going counterclockwise around the point .
The question concerns how the function changes, for real , if traces a closed contour going counterclockwise around the point (by analogy with problem 2482).
Study the change in as the point traces a simple closed contour going around the point in the positive direction.
Study the change in the function as the point traces a simple closed contour of one of three kinds:
going around one of the points ,
going around both of these points,
leaving these points outside the contour.
Find the increment of the argument of the function on the segment , given in the form , where
Find the increment of the argument of the function on the segment , given in the form , where
Compute the increment of the argument of the function along the oriented curve , given in the form , where
Compute the increment of the argument of the function along the oriented curve , given in the form , where
Compute the increment of the argument of the function along the oriented curve , given in the form , where
Compute the increment of the argument of the function along the oriented closed curve given by the equation
when it is traversed once counterclockwise.
Compute the increment of the argument of the function along the oriented closed curve given by the equation , when it is traversed once clockwise.
Prove the equality
for any simple piecewise-smooth closed curve such that the domain bounded by the curve contains the segment .