(commands used to generate figure above)

> p1:=arrow([1,-1],vector([4,1]),0.1,0.4,0.1,color=green):
p3:=arrow([1,-1],vector([1,-4]),0.1,0.4,0.1,color=red):
p2:=plot(1-2*x^2,x=-2..5,color=black):
p4:=textplot([5,-0.5,"grad(g)"],align={ABOVE,RIGHT},font=[TIMES,ROMAN,12]):
p5:=textplot([2.3,-4.8,"m"],align={ABOVE,RIGHT},font=[TIMES,BOLD,12]):
display([p1,p2,p3,p4,p5],view=[-2..6,-5.2..1],scaling=constrained,axes=framed);