Find the slope of the tangent to f(x)=cosxf(x) = \cos xf(x)=cosx at x=π3x = \frac{\pi}{3}x=3π.
−32-\frac{\sqrt{3}}{2}−23
32\frac{\sqrt{3}}{2}23
−12-\frac{1}{2}−21
12\frac{1}{2}21