Example

Finding the Intercepts of y=3x2+4x+4y = 3x^2 + 4x + 4

To find the intercepts of the parabola y=3x2+4x+4y = 3x^2 + 4x + 4:

Finding the y-intercept: Let x=0x = 0 and substitute it into the equation to solve for yy:

y=3(0)2+4(0)+4y = 3(0)^2 + 4(0) + 4 y=4y = 4

The y-intercept is the point (0,4)(0, 4).

Finding the x-intercepts: Let y=0y = 0 and solve for xx:

0=3x2+4x+40 = 3x^2 + 4x + 4

Calculate the discriminant (b24acb^2 - 4ac) with a=3a = 3, b=4b = 4, and c=4c = 4 to predict the number of x-intercepts:

b24ac=424(3)(4)=1648=32b^2 - 4ac = 4^2 - 4(3)(4) = 16 - 48 = -32

Because the discriminant is negative, the quadratic equation has no real solutions. Therefore, the parabola has no x-intercepts.

0

1

Updated 2026-04-21

Contributors are:

Who are from:

Tags

OpenStax

Elementary Algebra @ OpenStax

Ch.10 Quadratic Equations - Elementary Algebra @ OpenStax

Algebra

Math

Prealgebra

Related
Learn After