I. Function Keys

L. POLY

The Polynomial Root-Finder is a very useful function. It will solve up to a 30th-order real or complex polynomial. If the solutions are all real numbers, the answers will be given as single answers. If any or all of the solutions are complex numbers, then all of the solutions are given as complex ordered pairs.

Example: Use POLY to solve the equation .

Press
and press 3.
Enter the
coefficients
and constant.
Press
(SOLVE)

The solutions are x=2, x=-2, x=4/3.

Now let's look at a polynomial that has both real and complex solutions.

Example: Use POLY to solve the equation .

Press
and press 5.
Enter the
coefficients
and constant.
Press
(SOLVE)

The answers are given as ordered pairs, which means that there are complex solutions. The ordered pairs with a 0 as the second number are the real solutions. The others are complex solutions. The only real solutions are x=0 (a double root) and x=4.