
Tamara J. answered 12/06/12
Math Tutoring - Algebra and Calculus (all levels)
The vertex form of a quadratic function looks like the following:
y = a(x - h)2 + k , where (h, k) is the vertex of the graph of the function.
Given the graph of a quadratic function whose vertex is at (-5, 7), where -5 = h and 7 = k, we can write an equation for the quadratic function in vertex form:
y = a(x - h)2 + k , (h, k) = (-5, 7)
y = a(x - (-5))2 + 7
y = a(x + 5)2 + 7 ==> where a = 1
y = (x + 5)2 + 7
Now we can convert this into the standard form of a quadratic equation, which looks like the following:
y = ax2 + bx + c
y = (x + 5)2 + 7
y = (x + 5)(x + 5) + 7
y = (x2 + 5x + 5x + 25) + 7
y = x2 + 10x + 32 ==> where a = 1, b = 10, c = 32
Bart M.
08/10/16