what is the vertex of the graph of the function f(x) = x² + 8x - 2?\n(-4, 18)\n(0, -2)\n(-8, -2)\n(-4, -18)
what is the vertex of the graph of the function f(x) = x² + 8x - 2?\n(-4, 18)\n(0, -2)\n(-8, -2)\n(-4, -18)
Answer
Explanation:
Step1: Recall vertex - formula for a quadratic function
For a quadratic function (y = ax^{2}+bx + c), the (x) - coordinate of the vertex is (x=-\frac{b}{2a}). In the function (f(x)=x^{2}+8x - 2), (a = 1), (b = 8), and (c=-2). [x=-\frac{8}{2\times1}=-4]
Step2: Find the (y) - coordinate of the vertex
Substitute (x = - 4) into the function (f(x)=x^{2}+8x - 2). [f(-4)=(-4)^{2}+8\times(-4)-2=16-32 - 2=-18]
Answer:
D. ((-4,-18))