
John R. answered 01/08/13
John R: Math, Science, and History Teacher
The standard form of a parabolic function is given by the function:
f(x) = a(x - h)2 + k
The point (h,k) is the vertex of the parabola
a describes how the parabola opens: Positive opens up, negative opens down, If the absolute value of a is greater than one it is stretched vertically, If the absolute value of a is less than one it is stretched horizontally
Looking at your equation:
h is -2 (The number being subtracted from x
k is 1 (The number being added to the square term
a is 1 (Since nothing is written, the a value is understood to be one)
The vertex is at (-2,1), which means the graph has been moved left two and up one.