Question

How do you use the fundamental identities to simplify `sinphi(cscphi-sinphi)`?

Answer 1

`cos^2 t`

Explanation:

`f(t) = sin t(csc t - sin t) = sin t (1/sin t - sin t) =`
`= (sin t)(1 - sin^2 t)/(sin t) = cos^2 t`