What is the vertex form of #y= 3x^2-15x-14 #?

1 Answer
Mar 14, 2018

#y=3(x-5/2)^2-131/4#

Explanation:

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

#color(red)(bar(ul(|color(white)(2/2)color(black)(y=a(x-h)^2+k)color(white)(2/2)|)))#

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

#"to obtain this form use "color(blue)"completing the square"#

#• " the coefficient of the "x^2" term must be 1"#

#rArry=3(x^2-5x-14/3)#

#• " add/subtract "(1/2"coefficient of the x-term")^2" to"#
#x^2-5x#

#y=3(x^2+2(-5/2)xcolor(red)(+25/4)color(red)(-25/4)-14/3)#

#color(white)(y)=3(x-5/2)^2+3(-25/4-14/3)#

#color(white)(y)=3(x-5/2)^2-131/4larrcolor(red)"in vertex form"#