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**storpotaten** Hi guys, just found this site today and was hoping somebody here would have the time to help me out on what's probably a relatively simple problem...

I'm asked to evaluate the integral x/sqrt(1+4x) from 0 to 3. This seems innocent enough, and seeing as we've worked with substitutions recently I suspect I'm intended to head down that path.

However.. I can't get anything out of substituting u=1+4x; du ends up just being a constant (4) which isn't helping me any. I wonder if there's some trig substitution I'm just not seeing here.

Also, where can I get a guide on using the math tags?

thanks!