Question: Write the equation of a parabola having the vertex (1, −2) and containing the point (3, 6) in vertex form. Then, rewrite the equation in standard form.

[Hint: Vertex form: y - k = a(x - h)2]

Respuesta :

Answer:

[tex]y+2=2(x-1)^{2}[/tex] -----> vertex form

[tex]y=2x^{2}-4x[/tex] -----> standard form

Step-by-step explanation:

we know that

The equation of a vertical parabola in vertex form is equal to

[tex]y-k=a(x-h)^{2}[/tex]

where

(h,k) is the vertex of the parabola

In this problem we have

[tex](h,k)=(1,-2)[/tex]

[tex]Point(3,6)[/tex]

substitute the values and solve for a

[tex]6-(-2)=a(3-1)^{2}[/tex]

[tex]8=a(2)^{2}[/tex]

[tex]8=a(4)[/tex]

[tex]a=2[/tex]

the equation in vertex form is equal to

[tex]y+2=2(x-1)^{2}[/tex]

Find the equation of the parabola in standard form

we know that

the equation of the parabola in standard form is equal to

[tex]y=ax^{2}+bx+c[/tex]

we have

[tex]y+2=2(x-1)^{2}[/tex]

convert to standard form

[tex]y+2=2(x^{2}-2x+1)\\ \\y+2= 2x^{2}-4x+2\\ \\y=2x^{2}-4x+2-2\\ \\y=2x^{2}-4x[/tex]