Question

How do you simplify `cos(2theta)/(costheta-sintheta)`?

Answer 1

`=> color(green)(cos theta + sin theta)`

Explanation:

`cos (2theta) / (cos theta - sin theta)`

From the above table, `cos 2theta = cos^2 theta - sin^2 theta`

`=> (cos^2 theta - sin^2 theta) / (cos theta - sin theta)`

`=> (cancelcolor(red)(costheta - sin theta) * (cos theta + sin theta)) / cancelcolor(red) (cos theta - sin theta)`

`=> color(green)(cos theta + sin theta)`