Capt. Horatio T.P. Webb
QUADRATIC EQUATION
Solving by the Quadratic Formula and Graphing the Results
Comments and Suggestions to:
parks@uh.edu
Version 2.0 -- May 29, 2014
General Quadratic Equation Form:
ax
2
+ bx + c = 0
. This type of equation is called a parabola.
The solution for the two roots are calculated from the "quadratic formula":
The solution depends on the value of
b
2
- 4ac
. This term is called the "discriminant". There are three cases:
If
(b
2
- 4ac) > 0.0
, two real roots exist (i.e, the equation crosses the x-axis in two places -- the x-intercepts).
If
(b
2
- 4ac) < 0.0
, the real roots cannot the calculated since the equation does not cross the x-axis
(i.e. the quadratic formula above fails because the roots are
imaginary
-- they involve calculating the square
root of a negative number).
If
(b
2
-4ac) = 0
, then only one real root exists -- where the parabola touches the x-axis at a single point.
Enter values for:
a
b
and
c
Enter the desired number of digits to the right of the decimal
Calculated width/height of graph:
units
