definite integral

• May 2nd 2010, 02:34 PM
rhcp1231
definite integral
Evaluate the definite integral.

http://www.webassign.net/cgi-bin/sym...%28%20%29%20dx

I really am not sure how to evaluate this integral.

Do i use the substitution method and set my u = 1+2x?
• May 2nd 2010, 02:36 PM
Try $x=\frac{u^2}2 -\frac1{\color{red}2}$.

edit: whoops. Thanks Linnus.
• May 2nd 2010, 02:41 PM
rhcp1231

how did you get that x value?
• May 2nd 2010, 02:43 PM
Linnus
Wouldn't it be
$
u= \sqrt{1+2x}
$

$
u^2=1+2x
$

$
u^2-1=2x
$

$
x= (u^2-1)/2
$
• May 2nd 2010, 02:48 PM