How to solve these two questions of calculus?

1.

\fConsider the definite integral 5 cosh(6:r:) I = f d3 0 9 cosh2(6w) sinh(6:c) (a) Without performing any simplification inside the integral, rewrite the denominator using a hyperbolic identity, in terms of sinh(63) alone. The denominator becomes = D . (b) Substitute sinh(6$) = t . Hence, we have that _ bi _ a P(t) with a= ID b= D P(t)= ID (c) We could then compute I by applying the partial fraction decomposition to the integrand 1/P(t). How many terms do we expect in the decomposition? number of terms = a