Register to reply 
Integral ∫x^3*√(x^25) dx 
Share this thread: 
#1
Nov2512, 12:17 PM

P: 40

1. The problem statement, all variables and given/known data
∫x^3*√(x^25) dx 2. Relevant equations ∫u.dv=u.v∫du.v 3. The attempt at a solution So i tried to change the integral to ∫x*x^2*√(x^25)dx and u = x^25, then du = 2x, so 1/2*∫x^2*√(x^25) . Let u = √(x^25) , du = x/√(x^25) and dv = x^2 , v = x^3/3. Am I going in the right direction? Thanks in advance 


#2
Nov2512, 12:36 PM

Sci Advisor
HW Helper
Thanks
P: 25,251




#3
Nov2512, 12:49 PM

P: 40

1/2*∫(u+5)*√udu so I multiplied and I got : 1/2*∫u^(3/2)+5u^(1/2) 1/2*1/5 * ∫u^(3/2)+u^(1/2) and I got u^(5/2)/25+(2u^(3/2))/3 and It's wrong :/ where did I failed? Thanks 


#4
Nov2512, 12:56 PM

Sci Advisor
HW Helper
Thanks
P: 25,251

Integral ∫x^3*√(x^25) dx



#5
Nov2512, 12:59 PM

P: 40

The solution is supposed to be: x^3/3*(u^(3/2))2/15*(u^(5/2))+c 


#6
Nov2512, 01:08 PM

Sci Advisor
HW Helper
Thanks
P: 25,251




#7
Nov2512, 01:11 PM

P: 40

http://www.wolframalpha.com/input/?i...t%28x%5E25%29 


#8
Nov2512, 01:21 PM

Sci Advisor
HW Helper
Thanks
P: 25,251




#9
Nov2512, 01:24 PM

P: 40




#10
Nov2512, 01:31 PM

Sci Advisor
HW Helper
Thanks
P: 25,251




Register to reply 
Related Discussions  
Divergence Integral doesn't equal surface integral  Advanced Physics Homework  2  
Does path integral and loop integral in a Feynman diagram violate special relativity?  General Physics  0  
Rewrite the integral as an equivalent iterated integral in the order  Calculus & Beyond Homework  5  
Using polar coord. to change double integral into single integral involving only r.  Calculus & Beyond Homework  5  
Is the ordinary integral a special case of the line integral?  Calculus  3 