- #1

Lo.Lee.Ta.

- 217

- 0

2[itex]\pi[/itex]∫0 to 4 of (x)(√(4x) - (2x - 4))dx

= 2[itex]\pi[/itex]∫(2x

^{3/2}- 2x

^{2}+ 4)dx

When I Wolfram Alpha the answer, it is 448[itex]\pi[/itex]/15.

The computer HW system counts that answer as correct.

But when I try to take the integral, it's wrong! :(

I did this...:

2[itex]\pi[/itex](2x

^{5/2}/5/2 - 2(x

^{3})/3 + 4x

^{2}/4] |0 to 4

= 29.86[itex]\pi[/itex]

...This is not right. But what's the matter with my integration?

Thanks SO much for the help! :)