Question

How do you solve `x^2 - 2x - 24=0` graphically?

Answer 1

-4 and 6

Explanation:

To solve a quadratic equation graphically, we must know a few information:
a. a > 0, the parabola opens upward
b. The x-coordinate of the axis of symmetry, and the vertex:
`x = -b/(2a) = 2/2 = 1`.
c . The y-coordinate of vertex:
y(1) = 1 - 2 - 24 = -25 --> vertex (1, -25)
d. The y-intercept. Make x = 0 --> y = -24.
graph{x^2 - 2x - 24 [-10, 10, -5, 5]}
The graph gives 2 x-intercepts (real roots): -4 and 6.