How to draw a graph for function with constraints?

How can I draw the contour plot of the function z = 3x + 4y and the constraint curve x^2 + 4xy +5y^2 = 10 in the same figure ?

Answer 1

[Matt J]

 fimplicit(@(x,y) x.^2 + 4*x.*y +5*y.^2 - 10,'r'); hold on; fcontour(@(x,y) 3*x+4*y) ; hold off

[Trang To]

thank you so much

Answer 2

[Gurpreet Singh]

Hi Trang,

The following link might help you.

https://in.mathworks.com/matlabcentral/answers/487683-how-to-draw-a-3d-graph-with-constraints?s_tid=answers_rc1-1_p1_BOTH