y=-3x^2-6x+2
x0=-b/2a=-(-6)/2*(-3)=-6/6=-1
y0=-3(-1)^2-6(-1)+2=-3+6+2=5
y=-x^2+x-1
x0=-b/2a=-1/2*(-1)=1/2
y0=-(1/2)^2+1/2-1=-0.25+0.5-1=-0.75
y=5x^2-10x+4
x0=-b/2a=-(-10)/2*5=10/10=1
y0=5-10+4=-5+4=-1
y=-3x^2-6x+2
x0=-b/2a=-(-6)/2*(-3)=-6/6=-1
y0=-3(-1)^2-6(-1)+2=-3+6+2=5
y=-x^2+x-1
x0=-b/2a=-1/2*(-1)=1/2
y0=-(1/2)^2+1/2-1=-0.25+0.5-1=-0.75
y=5x^2-10x+4
x0=-b/2a=-(-10)/2*5=10/10=1
y0=5-10+4=-5+4=-1