Given: cos A = …eq. 1

d we know that _{tan A =}

We have value of cos A, we need to find value of sin A

Also we know that, sin A = √ (1-cos² A) …eq. 2

(∵, sin² θ +cos² θ =1

⇒ sin² A = 1-cos² A

⇒ sin A = √ (1-cos² A)

Thus,

Substituting eq. 1 in eq. 2, we get

Sin A =

Therefore,