(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Evaluate the integral:

the integral of 9r4^r dr

2. Relevant equations

integral of f(x)g'(x)dx = f(x)g(x) - integral of f'(x)g(x)dx

integral of udv = uv - integral vdu

u = f(x), dv = g'(x) dx

3. The attempt at a solution

I first started by pull the 9 out to the front:

9 integral of r4^r dr

I then set u=r, du=dr, dv=4^r, v=(4^r)/ln(4)

I used the formula: integral of udv = uv - integral vdu

and got: the integral of 9r4^r dr = [(r4^r)/ln4] - the inegral of (4^r)/ln4 dr

I then pulled the 1/ln4 out of the last part and got:

the integral of 9r4^r dr = [(r4^r)/ln4] - 1/ln4[the inegral of 4^r dr]

I was also able to get the anti-derivative of the [the inegral of 4^r dr] as (1/ln(4)) 4^r

I got stuck here, i don't know how to put all of it back together, help please?

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# Homework Help: Integral question

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