How do you write g(x)=2x^2+8x+13g(x)=2x2+8x+13 in vertex form?

1 Answer
Aug 25, 2017

g(x)=2(x+2)^2+5g(x)=2(x+2)2+5

Explanation:

"given the parabola in standard form "ax^2+bx+cgiven the parabola in standard form ax2+bx+c

"the x-coordinate of the vertex is"the x-coordinate of the vertex is

x_(color(red)"vertex")=-b/(2a)xvertex=b2a

2x^2+8x+13" is in standard form"2x2+8x+13 is in standard form

"with "a=2,b=8,c=13with a=2,b=8,c=13

rArrx_(color(red)"vertex")=-8/4=-2xvertex=84=2

"substitute this value into the equation for y-coordinate"substitute this value into the equation for y-coordinate

rArry_(color(red)"vertex")=2(-2)^2+8(-2)+13=5yvertex=2(2)2+8(2)+13=5

rArrcolor(magenta)"vertex "=(-2,5)vertex =(2,5)

"the equation of the parabola in "color(blue)"vertex form"the equation of the parabola in vertex form is.

•color(white)(x)y=a(x-h)^2+kxy=a(xh)2+k

"where "(h,k)" are the coordinates of the vertex and a"where (h,k) are the coordinates of the vertex and a
"is a constant"is a constant

"here "a=2" and "(h,k)=(-2,5)here a=2 and (h,k)=(2,5)

rArrg(x)=2(x+2)^2+5larrcolor(red)" in vertex form"g(x)=2(x+2)2+5 in vertex form