- #1

SUSUSUSUSUSUSUSU

## Homework Statement

The picture below.

## Homework Equations

cos2x=1-2sinx

sin2x= 2sinxcosx

## The Attempt at a Solution

I got the modulus by using the Pythagoras theorem which is 2sin theta

But I faced difficulty to find the argument. I have no idea why i end up with

**tan a (alpha) = cot theta**which is not the right answer. on the answer booklet, it's written that it is

**tan a =**I do not understand that why it comes to negative...? I just did tan a = sin2x/(1-cos2x) = cot x. Is it just because it is

__-cot theta__.**-isin2x**?I think after that i can solve it.

Thank you.