Using the following identities:

a) cosh^2(t)-sinh^2(t) = 1.

(b) cosh^2(t) = (1+cosh(2t))/2

(c) d/dt (cosh(t)) = sinh(t). dt

(d) d/dt (sinh(t)) = cosh(t). dt

Using the identities in question 1, calculate the integral tanh (t) sech (t) dt. Hint: Mimic how you would approach this problem for a trigonometric integral. Solution