A−B=π4A-B=\frac{\pi}{4}A−B=4π
A+B=π6A+B=\frac{\pi}{6}A+B=6π
A+B=π2A+ B=\frac{\pi}{2}A+B=2π
A−B=π2A-B=\frac{\pi}{2}A−B=2π