- #1

nzashadow

- 10

- 0

## Homework Statement

2/(tanx+cotx)=sinx

## Homework Equations

Double Angle Identities, Pythagorean Identities

## The Attempt at a Solution

2/(tanx+cotx)=

2/[(sinx/cosx)+(cosx/sinx)]=

2/[((sinx)^2+(cosx)^2)/(sinxcosx)]=

2sinxcosx/[(sinx)^2+(cosx)^2]=

2sinxcosx = sin(2x) =/= sinx

The book I'm getting this problem in says the answer is sinx, however I get sin(2x) which does not equal sinx. I am certain I am right, though I may also be making a stupid mistake :P