unitsize(2cm); import graph; pair F(real t) { return (1.3*t,-4.5*t^2+3.0*t+1.0); } pair Fprime(real t) { return (1.3,-9.0*t+3.0); } path g=graphwithderiv(F,Fprime,0,0.9,4); dot(g,red); draw(g,arrow=Arrow(TeXHead));