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View Full Version : [SOLVED] Simple Antiderivative


Icebreaker
Oct5-05, 11:31 PM
How would I compute the antiderivative of

\int \sqrt{1-\frac{x^2}{2}}

It looks familiar, but I can't quite remember how...

James R
Oct5-05, 11:46 PM
Put

x=\sqrt{2} \sin u

and go from there.

dextercioby
Oct6-05, 04:14 AM
U can also put the Riemann measure on \mathbb{R} : dx . :wink:

Daniel.

Icebreaker
Oct6-05, 02:16 PM
Ah yes, of course. Thanks.

Quick follow-up:

\int\log|\sqrt{1-x^2}+x|

James R
Oct6-05, 10:59 PM
I think that integrand is related to an inverse hyperbolic trig function... but I'd have to play around with it to work out which one. Maybe somebody else...

Icebreaker
Oct6-05, 11:03 PM
Perhaps it simply cannot be expressed algebraically?

amcavoy
Oct6-05, 11:07 PM
Perhaps it simply cannot be expressed algebraically?
It cannot be expressed in terms of elementary functions, you are correct.

I love Mathematica :smile:

Alex