Question 184593
the general vertex form of a quadratic is y = a(x-h)^2 + k


(h,k) is the vertex, and "a" controls what you call the "fatness"


your question is basically solving for "a"  __  algebra, not trial and error


y = a(x+2)^2 + 4


substituting (-1,8) ___ 8 = a(-1+2)^2 + 4


subtracting 4 ___ 4 = a


so the equation is ___ y = 4(x+2)^2 + 4