Hi(adsbygoogle = window.adsbygoogle || []).push({});

If I have the indefinite integral x(sqrt(4-x^2))dx

must I replace x with 2sint and then dx = 2cosdt

or can I just do regular substitution with u = 4-x^2 since xdx occurs in the integral already.

when I solve it this way I get -1/3(4-x^2)^3/2 + C

it just seems alot more work to do it the trigonometric substitituon way.

Any help is much appreciated. Thanks!!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Trig substition confusion

**Physics Forums | Science Articles, Homework Help, Discussion**