# Thread: i want some help for solve this

1. ## i want some help for solve this

2. any one i can be to choose
1 or 2 or 3 or 4

3. Hi fearsking

I think you can start by applying :$\displaystyle e^{\alpha\;i}=\cos\;\alpha + i\;\sin\;\alpha$

4. ## thanx songoku

i know that but i want second step or solve chooses
1 or 2 or 3 or 4

5. Hi fearsking

If you have applied the formula, then you'll have a form of |x + iy|. Find the modulus, then simplifying it using trigonometry identity