Channelle, Disinee and Abbey are love to challenge each other to more and more complication substitutions. They love the mental exercise they get from doing this. Even if they cannot evaluate the integrals, they know that it's wo the effort to understand the procedure. (a) Channelle challenges Disinee to apply the change of variable a = to to the indefinite integral sin(5x) - 9dx. Doing this Disinee obtains the integral Jo(t ) at where g(t) = . (Remember that the preview button can help you check your syntax) (b) Abbey has made a secret change of variables and now asks Disinee to work what what substitution will turn integral 2024 dr into the integral Au du? Disinee should use u = (c) Disinee decide to get revenge by challenging both Channelle and Abbey to apply the change of variable v = sin (c) to the definite integral sinh(42 + 6) da, knowing the result will not be a pretty formula. Doing this Channelle and Abbey obtain the integral P(v) du, where c