Quick integrating question (part of a series question)

[quickclick330]

Quick integrating question...(part of a series question)

Still studying for my exam...


Came across this example and I don't know what the method is for integrating this type of problem? (I'm using it to do the integral test for series). How did they get rid of the x^3? thanks for the help :-)

 

[ZioX]

Well what's the derivative of -1/3 * exp(-x^3)?

 

[HallsofIvy]

Or: let u= x² so that du= 3x² dx.

 

[quickclick330]

ahhh...i see it now. thanks :-)