I have forgotten my complex calculus

[mhicks3]

Can anyone help me with a complex calculus concept? I took this class years ago and cannot remember how to simplify something like $$\left|cos(1+2i)\right|$$^2?

Thanks!

Michael

 

[Office_Shredder]

If a is a complex number, |a|² = a * conjugate(a)

where if a=x+iy, conjugate(a) = x-iy.

So re-write cos(1+2i) in terms of exponentials and multiply... something good probably comes out the other side

 

[mhicks3]

Thanks! I'll try that. I think I actually remember now.

Michael