Theory Polar point (r,θ)(r,\theta)(r,θ) corresponds to rectangular coordinates: (x,y)=(rcosθ, rsinθ)(x,y)=(r\cos\theta,\ r\sin\theta)(x,y)=(rcosθ, rsinθ) If r<0r<0r<0 then: (r,θ)=(∣r∣,θ+π)(r,\theta)=\left(|r|,\theta+\pi\right)(r,θ)=(∣r∣,θ+π) Common exact values: cosπ6=32, sinπ6=12,cos5π12=6−24, sin5π12=6+24\cos\frac{\pi}{6}=\frac{\sqrt{3}}{2},\ \sin\frac{\pi}{6}=\frac{1}{2},\quad \cos\frac{5\pi}{12}=\frac{\sqrt{6}-\sqrt{2}}{4},\ \sin\frac{5\pi}{12}=\frac{\sqrt{6}+\sqrt{2}}{4}cos6π=23, sin6π=21,cos125π=46−2, sin125π=46+2