関連ワード:  what is cosh 2x sinh 2x    what is cosh 2 sinh 2    is cosh 2x sinh 2x 1    cosh 2x sinh 2x 1 proof    cosh 2x sinh^2x identity    cosh 2x sinh 2x formula    cosh 2x sinh 2x proof    what is cosh^2x    what is sinh cosh and tanh