What is the axis of symmetry and vertex for the graph #y=-3x^2-12x-3#?
1 Answer
May 10, 2018
Explanation:
#"given a quadratic in "color(blue)"standard form"#
#•color(white)(x)y=ax^2+bx+c color(white)(x);a!=0#
#"then the axis of symmetry which is also the x-coordinate"#
#"of the vertex is"#
#•color(white)(x)x_(color(red)"vertex")=-b/(2a)#
#y=-3x^2-12x-3" is in standard form"#
#"with "a=-3,b=-12" and "c=-3#
#rArrx_("vertex")=-(-12)/(-6)=-2#
#"substitute this value into the equation for y"#
#y_("vertex")=-3(-2)^2-12(-2)-3=9#
#rArrcolor(magenta)"vertex "=(-2,9)#
#rArr"axis of symmetry is "x=-2#
graph{(y+3x^2+12x+3)(y-1000x-2000)=0 [-20, 20, -10, 10]}
