Question

Notation is throwing me off???

Answer 1

I think what I have marked is right, that or one of the last two. See that little prime symbol at the original equation?

Answer 2

How can you get your answer?

Answer 3

Well, I just integrated. But that dumb prime is making me wonder which variation of it it is!!!

Answer 4

I want to see your work and to know why don't you trust yourself!! :)

Answer 5

Ok. Give me a sec.

Answer 6

9 ∫ x f'(x) dx

Let u =x and dv = f'(x) dx
So du = dx and v= f(x)

Then the integral becomes 9[xf(x) - ∫ f(x) dx]

Answer 7

btw, there are many experts here. They do intimidate me, hehehe....

Answer 8

so, what is wrong with it?

Answer 9

Yea, you are right. Just a bad overthinker.

Answer 10

:)

Answer 11

Thanks so much.