Question

Write the formula for the parabola that has x- intercepts (3,0) and (8,0), and y- intercept (0,−2)

Answer 1

Answer:$x^2-5x=-12(y+2)$

Step-by-step explanation:

Given

Parabola has x-intercept has $(3,0)$ and $(8,0)$

and Y-intercept as $(0,-2)$

Now the general equation of parabola is

$y=ax^2+bx+c\quad \ldots(i)$

Substitute  $(0,-2)$ in $(i)$ we get

$-2=c$

Now substitute $(3,0)$ in equation $(i)$

$0=a(3)^2+3b-2\quad \ldots(ii)$

Now substitute $(8,0)$ in equation $(i)$

$0=a(8)^2+8b-2\quad \ldots(iii)$

Solving $(ii)$ and $(iii)$ we get

$a=\frac{-1}{12}\ \text{and}\ b=\frac{5}{12}$

therefore

$y=\frac{-x^2}{12}+\frac{5x}{12}-2$

$12y=-x^2+5x-24$