Answer
True
Work Step by Step
$\cos$ 60$^{\circ}$ = 2 $\cos$$^{2}$ 30$^{\circ}$ - 1
$\cos$ 60$^{\circ}$ = $\frac{1}{2}$
$\cos$ 30$^{\circ}$ = $\frac{\sqrt3}{2}$
2 $\cos$$^{2}$ 30$^{\circ}$ - 1 = 2($\frac{\sqrt3}{2}$)$^{2}$ - 1
2 $\cos$$^{2}$ 30$^{\circ}$ - 1 = 2($\frac{3}{4}$) - 1
2 $\cos$$^{2}$ 30$^{\circ}$ - 1 = ($\frac{6}{4}$) - 1
2 $\cos$$^{2}$ 30$^{\circ}$ - 1 = ($\frac{3}{2}$) - 1
2 $\cos$$^{2}$ 30$^{\circ}$ - 1 = ($\frac{1}{2}$)
Thus:
$\frac{1}{2}$ = $\frac{1}{2}$
Therefore, $\cos$ 60$^{\circ}$ = 2 $\cos$$^{2}$ 30$^{\circ}$ - 1 is a true statement.
