hello : f(x) = a(x-k)²+k....... the point vertex is (h , k ) in this exercice : h = -3 and k = -1 s0 f(x) = a(x+3)²-1 find : a but f(0)=8 a(0+3)² -1 = 8 9a-1=8 9a =9 a=1 f(x) =(x+3)²-1 =x²+6x+9-1 f(x) = x²+6x+8 .... (the quadratic function in standard form )
