x value is going up and y value is moving up and down. So, it`s look like a quadratic function. y intercept is 12 and x intercept is 2 and 6. and vertex is (4,-4). than f(x)= a(x-4)^2+4. and put (0,12). and 16a+4=12. a=1/2. f(x)=1/2x^2-4x+12 or 1/2(x-4)^2+12