Question

( 1- cos² A ) sec² A = 1​

Answer 1

as we know(1-cos^2A) =sin^2A---1

and sec^2A= 1/cos^2A---2

from 1 and 2 we have

sin^2A/cos^2A=tan^2A---3

now according to question and using 1 2 and 3

tan^2A=1

:::A=45

Answer 2

Answer:

=(1- cos²A) sec²A

=sin²A sec²A

= sin²A/cos²A

=tan²A (A=45°)

=1