Question

What is the equation for this parabola (located above) in vertex form?

Answer 1

f(x)=x²-2x-2

Explanation:

f(x)=ax²+bx+c

f(0)=-2 => c= -2

f(1)= -3=> a+b-2=-3; a+b=-1

f(2)= -2; 4a+2b-2=-2; 4a+2b=0; 2a+b=0

a+b=-1 and 2a+b=0

2a+b-(a+b)=0+1=> a=1

2+b=0=> b=-2

f(x)=x²-2x-2