Quick Math Help

Question

1. When is a relation a function?

2. Write the following using function notation, “divide the input by 2, then add 1.

3. Graph the function using x- and y-intercepts. Given, , make a table, plot the points on a coordinate plane and graph the function

Answer 1

1)  A relation is function if every element in the domain maps to only element in the range.

 

2) f(x) = x/2 + 1

 

3)  the x-intercept happens when y=0. For this to happen, 0 = x/2 + 1 --->  -1 = x/2 ---> x = -2

     so the x-intercept is (-2,0)

 

   the y-intercept happens when x = 0. So f(0) = 1 ---> the y-intercept is (0,1)

 

    The slope of this line is 1/2 = rise/run; so up one, two to the right

 

 

      X         Y

 

    -2          0

 

   0             1

 

   2              2

 

   4              3 

 

notice I am choosing even numbers for X so it cancels the 1/2