A quadratic function f is given. f(x) = x2 16x + 48 (a) Express f in vertex form. f(x) = (b) Sketch a graph of f. The x y-coordinate plane is given. The curve enters the window in the third quadrant, goes up and right becoming less steep, crosses the x-axis at x = 12, changes direction at the point (8, 16), goes down and right becoming more steep, crosses the x-axis at x = 4, crosses the y-axis at y = 48, and exits the window in the fourth quadrant. The x y-coordinate plane is given. The curve enters the window in the second quadrant, goes down and right becoming less steep, crosses the x-axis at x = 16, changes direction at the point (8, 64), goes up and right becoming more steep, crosses the x-axis at the origin, and exits the window in the first quadrant. The x y-coordinate plane is given. The curve enters the window in the second quadrant, goes down and right becoming less steep, crosses the x-axis at the origin, changes direction at the point (8, 64), goes up and right becoming more steep, crosses the x-axis at x = 16, and exits the window in the first quadrant. (c) Find the maximum or minimum value of f. f(x) =