HP 39g+ - Manual (Page 53)

Aplets and their views 2-13
5. Press to zoom in
on the boxed area.
To set zoom factors 1. In the Plot view, press .
2. Press .
3. Select Set Factors... and press .
4. Enter the zoom factors. There is one zoom factor for
the horizontal scale (XZOOM) and one for the vertical
scale (YZOOM).
Zooming out multiplies the scale by the factor, so that
a greater scale distance appears on the screen.
Zooming in divides the scale by the factor, so that a
shorter scale distance appears on the screen.