Complex number problem with trig functions

  • Thread starter SlushmanIU
  • Start date
  • #1

Homework Statement


Find d^2/dx^2 and both complex number forms for the complex number equation (1+icos(x))/(1-icos(y))[/B]

Homework Equations


1. z=a+bi
2. re^itheta

The Attempt at a Solution


I have multiplied both sides by 1+icosy and gotten as far as (1+icosx+icosy-cosxcosy)/(1+cos^2y) but am going in circles after that. None of the trig identities seem to get me anywhere either.
 

Answers and Replies

  • #2
vela
Staff Emeritus
Science Advisor
Homework Helper
Education Advisor
14,883
1,461

Homework Statement

[/b]
Find d^2/dx^2 and both complex number forms for the complex number equation (1+icos(x))/(1-icos(y))
That's an expression, not an equation. There's no equal sign.

Homework Equations


1. z=a+bi
2. re^itheta

The Attempt at a Solution


I have multiplied both sides by 1+icosy and gotten as far as (1+icosx+icosy-cosxcosy)/(1+cos^2y) but am going in circles after that. None of the trig identities seem to get me anywhere either.
Multiplied both sides of what? Which problem are you trying to solve first?
 
  • #3
RUber
Homework Helper
1,687
344
Is the problem asking you to express the ##\frac {d^2}{dx^2} ## in terms of z and polar representations?
Are you starting with ##g : \mathbb{R}^2 \to \mathbb{C} : g(x,y) = \frac{ 1 + i cos x }{1-i cos y}=z ##?
The second derivative should be straightforward.
If you are simply trying to get into a : z = a+bi : form, your first attempt is sufficient to break the fraction into real (a) and imaginary (b).
 

Related Threads on Complex number problem with trig functions

  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
4
Views
2K
Replies
6
Views
7K
  • Last Post
Replies
6
Views
1K
Replies
5
Views
2K
  • Last Post
Replies
2
Views
10K
Replies
5
Views
2K
Replies
13
Views
10K
  • Last Post
Replies
3
Views
3K
  • Last Post
Replies
2
Views
2K
Top