HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010

Automatic vs. Build Your Own

ZOOM

Looking at the

NUM SETUP view you will see an entry called NumType with the default value of Automatic.

The alternative to Automatic is the setting of Build Your Own. Under this setting the

NUM view will be empty,

waiting for you to enter your own values for

Typing in the values of (for example):

3 ENTER (-) 2 ENTER 5 ENTER

… will give…

In this situation the function values are being calculated as you input the

X values. This can be quite useful if

you are wanting to evaluate the behavior of a function at selected points.

If you now use the

NUM SETUP view to switch to Automatic you will

find that there is a

key at the bottom left of the NUM view. This

can be quite useful as a fast way to reset the scale.

key pops up the menu on the right. The first option

of In causes the step size to decrease from 0.1 to 0.025. This is a

factor of 4 and is changeable via the

NUM SETUP view. I find a zoom

factor setting of 2 or 5 to be more useful.

Pressing the

The second option of Out causes the opposite effect, changing the step size upwards by whatever the Zoom

Factor is set to.

The Decimal option restores the default settings. It changes from whatever is showing back to the step size of

0.1 The Integer option on the other hand, changes the scale so the step size is 1.

exactly.

The Trig option changes the scale so that the step size is

This will obviously be useful when dealing with trigonometric functions

since it means that values such as

will appear exactly in the table.