Find the exact value of cos 7x/12

I suppose x should be π.

Recall the double angle identity for cosine:

Then remember for , we have .

Let . Plugging this into the equation above gives

Take the square root of both sides; this introduces two possible values, but we know should be positive, so

answer: a. 74

step-by-step explanation:

it shows divided evenly, so add the 37+37 = 74