Question

Write this expression in terms of sine and cosines and simplify? (Cosßtanß+1) (Sinß-1)

Answer 1

It simplifies to `-cos^2beta`.

Explanation:

Recall that `tanbeta = sinbeta/cosbeta`.

`=(cosbeta(sinbeta/cosbeta) + 1)(sin beta - 1)`

`=(sin beta + 1)(sinbeta- 1)`

`=sin^2beta - 1`

Recall that `sin^2x +cos^2x= 1`.

`=-cos^2beta`

Hopefully this helps!