Question

one x-intercept for a parabola is at the point (2, 0). use the quadratic formula to find the other x-intercept for the parabola defined by y=x^2-3x+2​

Answer 1

Answer:

Step-by-step explanation:

There are 3 ways to find the other x intercept.

1) Polynomial Long Division.

Divide x^2 - 3x + 2 by the binomial x - 2, because by the Factor Theorem if a is a root of a polynomial then x - a is a factor of said polynomial.

2) Just solving for x when y = 0, by using the quadratic formula.

$x^2 - 3x + 2 = 0\\x_{12} = \frac{3 \pm \sqrt{9 - 4(1)(2)}}{2} = \frac{3 \pm 1}{2} = 2, 1$.

So the other x - intercept is at (1, 0)

3) Using Vietta's Theorem regarding the solutions of a quadratic

Namely, the sum of the solutions of a quadratic equation is equal to the quotient between the negative coefficient of the linear term divided by the coefficient of the quadratic term.

$x_1 + x_2 = \frac{-b}{a}$

And the product between the solutions of a quadratic equation is just the quotient between the constant term and the coefficient of the quadratic term.

$x_1 \cdot x_2 = \frac{c}{a}$

These relations between the solutions give us a brief idea of what the solutions should be like.