# 3D Graph with Domain contours

Hi

I would like to visualize in 3D the function below:

f_{X,Y}(x,y) = \begin{array}{ll} x^2, & \mbox{if $1 \leq x \leq 2$ and $0 \leq y \leq x$}, \ 0, & \mbox{otherwise}. \end{array} .

I execute this code below, but it is not displaying good (what is wrong with the code ?), and how to display the axes labels ?

```
var("x y z")
region = implicit_plot3d(z, (x, -3, 3), (y, -3, 3), (z, -3, 3) , plot_points=100, region=lambda x,y,z: x^2 and 1<x and x<2 and y<x and y>0,axes=True)
region.show()
```

I just edited the code, I just realized that I forgot y> 0 !. I added it now. it seems that only the contour of the x,y domain is displayed, but not the z contour.