Just started learning integration, and although I can manage simple stuff, I've run into problems with some experiments of mine.(adsbygoogle = window.adsbygoogle || []).push({});

http://enes.fi/temp/circle.png [Broken]

The function for a circle is:

[itex]y = \sqrt{r^{2} - x^{2}}[/itex]

; and Wolfram gives the integral as:

[itex]\frac{1}{2}\left[x \cdot \sqrt{r^{2} - x^{2}} + r^{2} \cdot tan^{-1} \left(\frac{x}{\sqrt{r^{2} - x^{2}}}\right)\right][/itex]

This in turn results in:

[itex]f(b) - f(a) = f(s) - 0[/itex]

However, it's all wrong!

A radius of 10 means the area is approximately 78.540. Plugging in 10 into the equation results in division by zero. Even trying to integrate from 0 to 1, I get an area of 291.934, when it should be slightly less than 10!

Grrr! What am I doing wrong?

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# Simple integration

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