Use the intercept form of the equation of a parabola, y=a(x-p)(x-q).
y=1/10(x-12)(x+6)
Practice makes perfect
We want to write the equation of the parabola that passes through the point (14,4) and has x-intercepts 12 and - 6. To do so, we will use the intercept form of a quadratic function.
y=a(x-p)(x-q)
In this form, p and q are the intercepts. Therefore, we can partially write our equation.
y=a(x-12)(x-( - 6))
⇕
y=a(x-12)(x+6)
Finally, since the parabola passes through the point (14,4), we can substitute 14 for x and 4 for y in our partial equation to solve for a.
