関連ワード:  principal value of cot inverse 1    principal value of cot inverse 1 / 3    principal value of cot inverse (- 1 √ 3    principal value of cot inverse 1 root 3    principal value of cot inverse 1 2    principal value of cot inverse (-1/root 3)    principal value of cosecant inverse 1    principal value of cos inverse 1 2    principal value of cos inverse 1    principal value of cos inverse 1 √ 2