Finding the Intercepts of a Parabola
Y-intercept: Parabolas with an x squared term always either open upward
or downward and they only cross the y-axis in one place. Consequently, they
only have one y-intercept.
As usual, you calculate the y-intercept by setting x = 0 and solving.
Remember when you list the y-intercept it is always in the format (0, y).
X-intercept: To find the X intercept set y = 0 and solve. Depending on the
value of the discriminant b2 – 4ac, these parabolas can have 0, 1, or 2 xintercepts.
b2 – 4ac
To find the x-coordinate
Positive
Solve the quadratic
two x-intercepts
0
one x-intercept
no x-intercept
Negative
No real solutions