Question

if sin a = 2/5 , then find the value of cos a and tan a then ( 1 - cos² a / 1 + cos² a ) ( 1 - tan a / 1 + tan a ) ​

Answer 1

it is Given that cosA+cos

2

A=1⇒cosA=1−cos

2

A⇒cosA=sin

2

A.............(1)

Now, sin

2

A+sin

4

A=sin

2

A+(sin

2

A)

2

=sin

2

A+cos

2

A=1 (from (1))

Therefore, Answer is 1