Solve the following equations.
\cos\left(x\right) = \dfrac{-\sqrt{3}}{2}
\cos\left(x\right) = 0
\cos\left(x\right) = \dfrac{1}{2}
\cos\left(x\right) = 1
\cos\left(x\right) = \dfrac{\sqrt{2}}{2}
\cos\left(2x\right) = -1
\cos\left(x\right) = \dfrac{-1}{2}