Question

`(1 - tan^2(45^circ - A))/(1 + tan^2(45^circ - A))` is equal to ______.

पर्याय

• sin 2A

• cos 2A

• tan 2A

• cot 2A

Answer 1

`(1 - tan^2(45^circ - A))/(1 + tan^2(45^circ - A))` is equal to sin 2A.

Explanation:

`(1 - tan^2(45^circ - A))/(1 + tan^2(45^circ - A))`

= `(cos^2 (45^circ - A) - sin^2 (45^circ - A))/(cos^2 (45^circ - A) + sin^2 (45^circ - A))`

= `(cos 2 (45^circ - A))/1`

= sin 2A