How do you find the vertex of y = 3x^2 -6x-4y=3x26x4?

1 Answer
Jul 15, 2015

Convert to vertex form to obtain the vertex at (1,-7)(1,7)

Explanation:

The easiest way to solve this requirement is to rewrite the equation into vertex form:
color(white)("XXXX")XXXXy = m(x-a)^2+by=m(xa)2+b
color(white)("XXXX")XXXXcolor(white)("XXXX")XXXXwhich will have a vertex at (a,b)(a,b)

Given y = 3x^2-6x-4y=3x26x4

Extract mm
color(white)("XXXX")XXXXy = 3(x^2-2x) -4y=3(x22x)4

Complete the square by adding 3(1)3(1) and then subtracting 33 as
color(white)("XXXX")XXXXy = 3(x^2-2x+1) -4 -3y=3(x22x+1)43

Rewrite as a squared binomial and simply
color(white)("XXXX")XXXXy = 3(x-1)^2 + (-7)y=3(x1)2+(7)

Since this is in vertex form, we can simply read the vertex off as:
color(white)("XXXX")XXXX(1,-7)(1,7)