**Factor**

Press **MENU 9** to access the CAS screen.
Press **F1** to access the TRNS (transform) menu. Press **3** to select
item **3:factor**. The prompt factor( is pasted into the entry line.

The
syntax for factoring an algebraic expression is factor(expression). For example,
let's factor *x** *^{4} - 1. After the prompt **factor(**
in the entry line, type

X ^ 4 - 1 , X ) EXE

Hence, .

The item 3:factor initially provides a factorization over the integers. Hence,
factor(x^4 - 9) is returned as (x^{2} - 3)(x^{2} + 3). To obtain
a factorization over the real numbers, from the TRNS menu, press **2** to select
2:rFctor. This yields the desired complete factorization over the real numbers.

In
order to obtain a complete factorization over the complex numbers, press **CTRL
SETUP**, highlight Answer Type, press **F2** to select CPIX, then
press **EXE**. This returns you to the CAS screen.

Press **F2** to select the TRNS menu, press **2** to select 2:rFctor
and paste rFactor( into the entry line. Enter the expression, close the parenthesis,
and press execute. For example, enter **X ****^**** 4 - 9 , X ) EXE**
to factor x^{4} - 9. The factorization

is displayed.

**Factor a Number**

When
applied to a number, factor displays the prime factorization of a given integer.
To factor an integer into its prime number factors, press **F1** to access
the TRNS menu. Press **3** to select **3:factor**. The syntax for factoring
is factor(integer). For example, the screen at right displays the prime factorization
for *n* = 1234567890.