## 1.2. Relations and Functions

### Example 1.2.5(d):

If we draw the graph of the function and shade the interval [-2, 2] on the*x*axis (in red) then its projection onto the

*y*axis will be the image (in green).

**image([-2, 2]) = [0, 4]**

*y*axis (in red) then its projection onto the

*x*axis will be the preimage (in green).

**preimage([-2, 2]) = [-sqrt(2), sqrt(2)]**