Question 73929
<pre>
Written Exercises#6,14,30,38 Pgs.386-387 

6.Draw the graph of the linear function n(x)=0

{{{graph (200, 200, -3,5, -4, 4, 0, 0)}}}

The graph is a vertical line along y-axis



14.For the function f(x)= 4x-x^2 find the coordinates of the vertx, graph the equation.

Vertex : f(x)= 4x-x^2. remember the standard form of a quadratic equation
 ax^2 + bx + c = 0. Rewrite f(x)= 4x-x^2 in standard form f(x) = -x^2 + 4x + 0
a = -1, b = 4, c = 0

 Formula for solving the vertex :  
                     -b
                x = ____
                     2a
                   
                     -4
                 = _______
                    2(-1)

                     -4
                 = _______ or 2
                     -2

Using x = 2 substitute it to 

         f(x)= 4x-x^2
             = 4(2) - (2^2)
             = 8 - 4
             = 4

Vertex is (2, 4)

{{{graph (200, 200, -4, 9, -8, 6, 4x-x^2)}}}
   

30. For the equation y= 6+6x-1/3x^2 find the vertex and the axis of symmetry

Can you give me the right equation?



38. For the function f(x) = x^2-8x+15 find f(0); x = 0

     f(0) = 0^2 - 8(0) + 15
          = 15