Respuesta :

Answer:

8/√113

Step-by-step 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