f(x) = -16x^2 + 8x + 3

Part A: What are the x-intercepts of the graph of the f(x)? Show your work. (2 points)

Part B: Is the vertex of the graph of f(x) going to be a maximum or minimum? What are the coordinates of the vertex? Justify your answers and show your work. (3 points)

Part C: What are the steps you would use to graph f(x)? Justify that you can use the answers obtained in Part A and Part B to draw the graph. (5 points)

Question

f(x) = -16x^2 + 8x + 3

Part A: What are the x-intercepts of the graph of the f(x)? Show your work. (2 points)

Part B: Is the vertex of the graph of f(x) going to be a maximum or minimum? What are the coordinates of the vertex? Justify your answers and show your work. (3 points)

Part C: What are the steps you would use to graph f(x)? Justify that you can use the answers obtained in Part A and Part B to draw the graph. (5 points)

ranga · Answer

To find the x-intercepts, set y = 0 and solve for x.  (y is same as f(x))

mathmale · Answer

Right.  Setting -16x^2 + 8x + 3 = 0, we can slightly simplify the task ahead by changing all the signs:  16 x^2 - 8 x - 3 = 0.

What ways do you know of solving this quadratic equation for x?  

Once you'd done that, and found the two roots, you'll need to write the x-intercepts as points:  (x0, f(x0)) and (x1, f(x1)).