Question

If q is between 0º and 90º and tan (theta) = 7/8 find cos (theta)

Answer 1

8/√113

Explanation:

0< θ < 90 degree; tan (θ) = 7/8 find cos (θ)

Using the identity

1 + tan²θ = sec²θ (where sec θ = 1/cosθ)

cosθ = √{1/(1 + tan²θ)} = √{ 1/(1 + (7/8)²} = √{ 1/(1 + 49/64)}

= √{ 64/113} = 8/√113