Question

I have an hour to finish, help a girl out

Answer 1

If you're going to use technology (Brainly) to solve this problem, you might find you get a quicker answer using the technology of your graphing calculator.

It is often convenient to cast the problem in the form f(θ) = 0. You can do that by adding 1 to both sides of the equation.

$4\sqrt{2}\cos{(\theta)}+4=0\\ \cos{(\theta)}+\dfrac{1}{\sqrt{2}}=0\qquad\mbox{divide by 4\sqrt{2} }\\ \cos{(\theta)}=\dfrac{-\sqrt{2}}{2}\qquad\mbox{subtract \dfrac{1}{\sqrt{2}} }\\\\ \theta=\{\dfrac{3\pi}{4},\dfrac{5\pi}{4}\}\qquad\mbox{determine the corresponding angles}$