Matlab 3D图平方？

Question

How to plot a 3d graph of a quadratic funciton. Here is my code for the 2D plot is there anyway to adapt it for a 3d code ?

z = (startv2:step:endv2);
y = (a2.*(z.^2))+(b2.*z)+c2;
plot(z,y);
text(value1,0, ['X1 = ',num2str(value1),' ']);
text(value2,0, ['X2 = ',num2str(value2)]);
grid

Answer 1

These MATLAB functions might help:

plot3

or

contour3

or

surf

depending on what you want to show. The MATLAB help (click on the functions above) has examples for all of them.