Sagemath for Multivariable Calculus

%display latex
#Plotting Vector Field
F(x,y)=[cos(x),sin(x)]
plot_vector_field(F,(x,-3,3),(y,-3,3))

# Finding Curl and Divergence of Vector Field
F(x,y,z)=[x*y, y*z, x*y*z]
F.curl()
F.div()

#Contour Plot
f=x^2-y^2
contour_plot(f,(x,-4,4),(y,-4,4))