Question #21f0f
1 Answer
Nov 7, 2017
Explanation:
#"given a parabola in standard form "color(white)(x);y=ax^2+bx+c#
#"the x-coordinate of the vertex is"#
#•color(white)(x)x_(color(red)"vertex")=-b/(2a)#
#y=-2x^2+4x+1" is in standard form"#
#"with "a=-2,b=4,c=1#
#rArrx_(color(red)"vertex")=-4/(-4)=1#
#"substitute this value into the equation for y"#
#rArry_(color(red)"vertex")=-2+4+1=3#
#rArrcolor(magenta)"vertex "=(1,3)#
graph{-2x^2+4x+1 [-10, 10, -5, 5]}