1. Substitution. Consider the integral sinh(x )cosh(x) dx a) Evaluate the integral by making the substitution u = sinh(x). b) Evaluate the integral by making the substitution u = cosh(x). c) Use the identity sinh(2x) =2sinh(x )cosh(x) to rewrite the integrand and then evaluate the integral by making the substitution u = 2x. d) Explain the relationships between the antiderivatives from (a), (b), and (c)