Trigonometry
Determine the exact value of the given inverse trigonometric function without using a calculator.
y=cos−1(−12)+cos−1(−1)y=\cos^{-1}\left(-\frac12\right)+\cos^{-1}\left(-1\right)y=cos−1(−21)+cos−1(−1)
y=2π3y=\frac{2\pi}{3}y=32π
y=5π3y=\frac{5\pi}{3}y=35π
y=−π3y=-\frac{\pi}{3}y=−3π
y=πy=\piy=π