Question

Express your answer exactly

Answer 1

cos(Θ) = 84/85

Explanation:

See the attachment.

Sine is opposite divided by hypotenuse. Here, the "opposite" side is -13 and the hypotenuse is 85. Cosine is adjacent divided by hypotenuse. The "adjacent" side is the unlabelled length. We find this by using the Pythagorean Theorem:

b =
`√(85^2-(-13)^2) =√(7225-169) =√(7056) =84`

So, cos(Θ) = 84/85

Hope this helps!