Lockup Calculating Arc Length of Ellipse

[parisse]

Checked with the latest version of Xcas:
int(sqrt(4*(sin(t))^2 + (cos(t))^2),t,0,2*pi)
returns integrate(sqrt(5/2-3/2*cos(2*t)),t,0,2*pi)
while
int(sqrt(4*(sin(t))^2 + (cos(t))^2),t,0.,2*pi)
returns 9.68844822055
I'll check tomorrow on the calc. The firmware is a bot old now compared to the latest version of Xcas, many bugs have been fixed in Xcas...