Still not getting this calc trig identity please help!!?

Evaluate the indefinite integral.


[INT] 39cos^(3)(97x)dx





i know it gets separated and than you substitute but i am getting a crazy answer with sin and cos which doesn't make the integral any easier so i must be doing something wrong! i'm getting:





13sin(97x)^3 - (39/97)cos (97x) + c





PLEEEEEEEEASE HELPPPP!!!





Also still need help with





[INT FROM 0 to 1] x^(2)((fifth route)e^(x)) dx





and





[INT FROM 1 to 6] sq route(t) lntdt





Sorry to be annoying, I've been outta school 4 years and this was not the easiest thing to get thrown back into but no fear, I signed up for a tutor starting next week!

Still not getting this calc trig identity please help!!?
It is an example in Salas and Hillle's 7th ed. p. 504, but have no idea how to type the notation. Look in your text for "reduction formulas" or in the index under "Integration, trigonometric functions, powers and products of"

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