Example

Finding the Intercepts of y=9x2+12x+4y = 9x^2 + 12x + 4

To find the intercepts of the parabola given by y=9x2+12x+4y = 9x^2 + 12x + 4:

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

y=9(0)2+12(0)+4y = 9(0)^2 + 12(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 the resulting quadratic equation for xx:

0=9x2+12x+40 = 9x^2 + 12x + 4

Solve the equation by factoring the perfect square trinomial:

0=(3x+2)20 = (3x + 2)^2

Use the Zero Product Property by setting the repeated factor equal to zero:

3x+2=03x + 2 = 0 3x=23x = -2 x=23x = -\frac{2}{3}

Because there is only one real solution, the parabola touches the x-axis at a single point. The x-intercept is (23,0)(-\frac{2}{3}, 0).

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Updated 2026-04-21

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