# Question:Separating a curve into a dashed and a solid line at a specific point

## Question:Separating a curve into a dashed and a solid line at a specific point

Maple

Hey,

suppose I have got two quadratics varying with variable Q1 and two quadratics varying with Q2,

eg. P1=a+b*Q1^2 and P11=c+d*Q1^2

P2=e+f*Q2^2 and P22=g-h*Q2^2

where a,b,c,d,e,f,g and h are finite constants such that curves P1 and P11 intersect at two values of Q1, one being negative and the other positive. The same is true for curves P2 and P22. Now, I can plot curves P1 and P2 on a 3D plot (x-axis = Q1 and y-axis=Q2 and z-axis=P1=P2) such that I get two rising parabolas, which are orthogonal to each other as P1 is over the Q1 axis and P2 over the Q2 axis.I do this as follows,

plot3d([[0,Q2,P2],[Q1,0,P1]],Q1=-1..1,Q2=-1..1,axes=standard);

What I want, is to have Maple plot line P1 with a solid line when P1 < P11 and plot P1 with a dashed line once P1 > P11. Thus P1 is a solid line until the intersection point Q1 at which P1=P11.

The converse applies to P2. Therefore, have Maple plot line P2 with a dashed line when P2 < P22 and plot P2 with a solid line once P2 > P22. Thus P2 is a dashed line until the intersection point Q2 at which P2=P22.

In Matlab you would assign a handle to the graph such that I could update the plot3d command I have given above. Unfortunately I'm new to Maple and not quite sure how to do it.