Quadratic Equations

The { QAD } selection requires you to enter the coefficients of your equation. An equation in quadratic form has coefficients a, b, and c.:

ax² + bx + c = 0.

Finding Quadratic Roots

Select { QAD } from the EXTENDED FUNC menu to display the QUADRATIC EQN menu.
D_md9iRQ

Enter the value of the a coefficient and select { a }.
Enter the value of the b coefficient and select { b }.
Enter the value of the c coefficient and select { c }.
Select { XEQ }. One of the menus below is displayed.
If the roots are real, display the two roots by selecting:
{ R1 } - the first real root.
{ R2 } - the second real root.
If the roots are complex, display the real and imaginary parts by selecting:
{ Re } - the real part.
{ Im } - the imaginary part.

The two roots are Re + (Im)i and Re - (Im)i.

Data registers 000, 001, and 002 are used to store both the inputs and the results. As the values for a, b, and c are entered, they are stored in registers 000, 001, and 002, respectively. After the two roots are determined, they are stored in registers 000 and 001. Register 002 contains a 0 if the roots are real and a 1 if the roots are complex. Therefore, the original inputs are no longer available in these registers.

Quadratic Example

Find the roots of the equation 4.2x² + 0.22x + 8 = 0.

Procedure	Press	Display
Clear display	[ CLEAR ]
Select quadratic roots	[ FUNC ] { QAD }
Enter value for a	4.2 { a }
Enter value for b	.22 { b }
Enter value for c	8 { c }
Determine roots	{ XEQ }
Display real part	{ Re }
Display imaginary part	{ Im }