3^rd Degree Polynomial Calculator

Example 1

For the polynomial Fx = -2 -1.5*x + 0.75*x^2 + 0.25*x^3

find f(3) and the roots.

Value	Key	Display	Description
-2	C0	-2.0000	Stores the C0 value.
-1.5	C1	-1.5000	Stores the C1 value.
.75	C2	0.7500	Stores the C2 value.
.25	C3	0.2500	Stores the C3 value.
3	X	3.0000	Stores the X value.
	f(x)	7.0000	Calculates Fx(3).

Example 2

Find the root nearest to x = 3.

These keystrokes assume the values from example 1.

Value	Key	Display	Description
0	f(x)	0.0000	Stores the Fx value.
	X	2.0000	Calculates a root.

Example 3

Find the root nearest to x = -3.

These keystrokes assume the values from examples 1 and 2.

Value	Key	Display	Description
-3	X	-3.0000	Stores a new initial guess.
	X	-4.0000	Calculates a root.

Example 4

Find the root nearest to x = 0.

These keystrokes assume the values from examples 1 and 2.

Value	Key	Display	Description
0	X	0.0000	Stores a new initial guess.
	X	-1.0000	Calculates a root.

Plotting

Create a graph of for x = -5 to 3

Value	Key	Display	Description
-5	= or ENTER	-5.0000	Enters first value of the range.
3	shift f(x)	plot	Enters the second value of the range, selects the independent variable for the plot.

This will produce the following plot: