Practice problem
If cos(x)=23\cos(x)=\frac23cos(x)=32 and xxx is in quadrant I, then find an exact value for cos(2x).\cos(2x).cos(2x).
−19-\frac{1}{9}−91
−29-\frac{\sqrt2}{9}−92
−39-\frac{\sqrt3}{9}−93
−29-\frac{2}{9}−92
Type a concept, like “slope” or “photosynthesis”.
