# What is the vertex of # y= -(x+1)^2+2x^2-x #?

##### 1 Answer

Jan 13, 2018

#### Explanation:

#"expand and simplify right side of the equation "#

#y=-(x^2+2x+1)+2x^2-x#

#color(white)(y)=-x^2-2x-1+2x^2-x#

#color(white)(x)=x^2-3x-1larrcolor(blue)"in standard form"#

#"with "a=1,b=-3" and "c=-1#

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

#•color(white)(x)x_(color(red)"vertex")=-b/(2a)=-(-3)/3=3/2#

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

#y_(color(red)"vertex")=(3/2)^2-3(3/2)-1=-13/4#

#rArrcolor(magenta)"vertex"=(3/2,-13/4)#