Precalculus
Improve your experience by picking them
Evaluate the expression.
cos−1(−22)\cos^{-1}\left(-\frac{\sqrt2}{2}\right)cos−1(−22)
π4\frac{\pi}{4}4π
3π4\frac{3\pi}{4}43π
5π4\frac{5\pi}{4}45π
7π4\frac{7\pi}{4}47π