PDE - Complex numbers

[Larrytsai]

Homework Statement

Simplify the expression

e^(i6theta)[ (1+e^(-i10theta))/(1+e^i2theta)]

Answer should be in terms of cosines

but i dont know how to start this problem? :S

Also, does e^(-iwt) = - coswt -jsinwt?

K so Im thinking about Eulers formula, and I get an expression with Sines and cosines not just cosines =s

 

[tiny-tim]

Hi Larrytsai!

(hav a theta: θ and try using the X² icon just above the Reply box )

hint: use Euler's formula and standard trigonometric identities to simplify 1 + e^2iθ

(oh, and e^-iθ = cosθ - isinθ)