- #1

Crystal037

- 165

- 7

**Homework Statement:**(cos2A -1)/sinA +sin2A/(cos2A+1)*cosA=__________________

**Homework Equations:**sin2A=2sinAcosA

cos2A+1=cos^2A

cos2A-1=sin^2A

(cos2A -1)/sinA +sin2A/(cos2A+1)*cosA

[cos^2(2A)-1 +2sin^2(A)cos^2(A)]/sinA(cos2A+1)

[-sin^2(2A) + 2sin^2(A)cos^2(A)]/sinA(cos2A+1)

I can't proceed any further.

The answer must be 2 sin^2A