Nitin P. answered 05/30/20
Machine Learning Engineer - UC Berkeley CS+Math Grad
1.) The equation is in vertex form, so the vertex is at point (h, k) for the quadratic function f(x) = a(x-h)2 + k. Therefore, in this case, the vertex is at point (5,3). You can find 2 other points simply by choosing 2 other values of x, and plugging them into the function to find their corresponding y-values, giving you two other points on the parabola. (Ex.: (6,5), (7,11))
2.) The factored form gives you the x-intercepts of the function. a and b are x-intercepts of the function f(x) = (x-a)(x-b), therefore the x-intercepts here are 5 and -3. Now, the x-coordinate of the vertex will always be halfway between the two x-intercepts, or in this case (5-3)/2 = 1. Plug this value into the function to get (1-5)(1+3) = -16, therefore the vertex is at (1,-16). Therefore, 3 points on the graph are (5,0), (-3,0), and (1,-16).
3.) The zeros of a quadratic function are the x-intercepts, which are directly given by the factored form of the function. We can factor the given function as:
x2 + 10x - 24 = (x+12)(x-2) = 0
Since we are multiplying 2 terms with a result of 0, at least one of the two terms must be 0, therefore we have:
x + 12 = 0
x - 2 = 0
Therefore, the zeros of the function are x = -12 and x = 2.