Question

Question #ebba1

Answer 1

Develop the Numerator of the left side:
`NLS = sin u/(cos u) - cos u/(sin u) =`
`= (sin^2 u - cos^2 u)/(sin u.cos u)`
Develop the Denominator of the left side:
`DLS = sin u/(cos u) + cos u/(sin u) =`
`= (sin^2 u + cos^2 u)/(sin u.cos u)`
`(NLS)/(DLS) = (sin^2 u - cos^2 u)/(sin^2 u + cos^2 u) =`
`= sin^2 u - cos^2 u`