平面切圆柱面的椭圆绘制

t=-sqrt(12):0.0001:sqrt(12);
x=t;
y=sqrt(12-t.^2);
z=2*t + 3*y;
plot3(x,y,z);
hold on
y1=-sqrt(12-t.^2);
z=2*t + 3*y1;
plot3(x,y1,z);
grid on
 axis equal