関連ワード:  derivative of 1/cosh x    derivative of 1 cosh x    derivative of cosh 1 x 3    derivative of cosh^-1 ( x^2)    derivative of 1 sinh x    derivative of sinh 1 cosh x    differentiation of cosh 1 x    derivative of sinh(1-x^2)    derivative of sinh 1 x 3    differentiation of sinh 1 x