Question

Prove that Sec²(90°- A) -
1/tan²A =1​

Answer 1

Answer:

LHS

sec² ( 90 - a ) - 1 / cot² ( 90 - a )

= cosec²a - 1 / tan²a

= cot²a / tan²a { °.° cosec²a - 1 = cot²A }

= 1 / tan²a / tan²a { °.° cot²a = 1/tan²a }

= tan²a / tan²a

= 1

RHS

proved