integrate bug



On 02/01/2012 12:04 PM, Aleksas Domarkas wrote:
> Integrate bug:
>
> (%i1) integrate(acos((x-1/2)/sqrt(1-x^2)), x, 0, 1/2);
> (%o1) -%pi/4
> (%i2) float(%), numer;
> (%o2) -0.78539816339745
>
> (%i3) quad_qags(acos((x-1/2)/sqrt(1-x^2)), x, 0, 1/2);
> (%o3) [0.9161228399914,1.0171006703434392*10^-14,21,0]

And:

(%i2) integrate (acos ((x-1/2)/sqrt (1-x^2)), x);
(%o2) -%pi*x/2

which is obviously wrong.

Jaime