Question

(1+tan²A) (1-cos²A),_​

Answer 1

Tan²A.

(1 + tan²A) (1 - cos²A)

1 + tan²A = Sec² and 1 - Cos²A = Sin²A, so,

= Sec²A × Sin²A

Since Sec²A = 1/Cos²A, replacing Sec²A by 1/Cos²A.

= 1/Cos² × Sin²A

= Sin²A / Cos²A

= Tan²A.