(adsbygoogle = window.adsbygoogle || []).push({}); [SOLVED] Integral of {sqrt(4-x^2)} from 0 to 2?

Can someone please explain step by step for this?

I know the answer is pi, I just don't understand the steps towards solving it

First, I'm supposed to set x = 2sin(u)

so then u = arcsin(x/2)

then somehow, {sqrt(4-x^2)} = 2cos(u)

How'd that happen? @__@

I'm really really confused!

Thanks for tolerating XD

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

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: Integral of {sqrt(4-x^2)} from 0 to 2?

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