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?

Try $\displaystyle x=\frac{u^2}2 -\frac1{\color{red}2}$.

edit: whoops. Thanks Linnus.

[quote=maddas;505552]Try [tex]x=\frac{u^2}2 -1

how did you get that x value?

Wouldn't it be
$\displaystyle
u= \sqrt{1+2x}
$
$\displaystyle
u^2=1+2x
$
$\displaystyle
u^2-1=2x
$
$\displaystyle
x= (u^2-1)/2
$

[QUOTE=rhcp1231;505555]

Quote:

---

Originally Posted by maddas

Try [tex]x=\frac{u^2}2 -1

how did you get that x value?

---

I chose it so that the square root on the bottom would disappear, ie I wanted 1+2x = u^2. But like Linnus pointed out, I lost the 1/2. heh.