2(π4−23)2\left(\frac{\pi}{4}-\frac{2}{3}\right)2(4π−32)
2(π4+23)2\left(\frac{\pi}{4}+\frac{2}{3}\right)2(4π+32)
π4−23\frac{\pi}{4}-\frac{2}{3}4π−32
π4+23\frac{\pi}{4}+\frac{2}{3}4π+32