Kenneth S. answered • 11/16/17

Calculus will seem easy if you have the right tutor!

Do you know the correct approach to this kind of question?

Draw a right triangle situated in the first quadrant, for which tan θ = 15/8.

Thus the hypotenuse will be 17 (this is one of the Pythagorean triples).

Note: you are being asked to get cos θ BECAUSE θ = ARCTAN 15/8.

Do you see it?

You can even check this on your calculator.