I let
f(x)=cos(x)
and calculate the (2,4) Padé approximation of f:
f.taylor(x,0,10).power_series(QQ).pade(2,4)
Sage answers with
(-244/3x^2 - 1/1512000x + 200)/(x^4 - 1/18144000x^3 + 56/3x^2 - 1/1512000*x + 200)
which seems incorrect. (The Taylor series of this rational function has a x^3 term which differs from that of f.)
Am I doing something wrong, or is there a problem with sage?
