Find the equation (f(x)=a(x-h)^2+k) for a parabola containing point (2,-1) and having (4,-3) as a vertex. what is the standard form of the equation a.)the vertex form is f(x)=x^2-3. the standard form is f(x)=1/2x^2-4x+6 b.)the vertex form is f(x)=1/2(x-3)^2+4 . the standard form is f(x)=x^2-4x+5 c.)the vertex form is f(x)=1/2x^2-4x+3. the standard form is f(x)=1/2x^2-4x-8 d.)the vertex form is f(x)=1/2(x-4)^2-3. the standard form is f(x)=1/2x^2-4x+5