Question

-2cos ∅=-3-8cos ∅ solve each equation for 0≤∅≤2π

Answer 1

`\large\boxed{\Theta=(2\pi)/(3)\ \vee\ \Theta=(4\pi)/(3)}`

Explanation:

`-2\cos\Theta=-3-8\cos\Theta\qquad\text{add}\ 8\cos\Theta\ \text{to both sides}\\\\6\cos\Theta=-3\qquad\text{divide both sides by 6}\\\\\cos\Theta=-(3)/(6)\\\\\cos\Theta=-(1)/(2)\\\\\text{look at the picture}\\\\\Theta=(2\pi)/(3)\ \vee\ \Theta=(4\pi)/(3)`