関連ワード:  differentiation of cosh 2x    differentiation of sinh 2x    derivative of ln cosh^2x    derivative of 1/cosh^2x    derivative of cosh 3 2x 3    derivative of cosh^2 2x    derivative of cosh inverse 2x    what is the derivative of cosh    what is cosh^2x    what is the derivative of cosh(x)