Question

Cos (90-α)sin(90-α)/tan(90-α)=sinsquareα

Answer 1

1) cos (90-a) = sin a
sin (90-a) = cos a
tan(90-a) = cot a
so equation becomes
sin a × cos a ÷ cot a
sin a ×cos a ÷ cos a /sin a. (as cot = cos / sin )
sin goes to numerator
it becomes
sin a × sin a ×cos a ÷ cos
cos gets cancelled
And ans is sin^2 a
lhs = rhs