function below relates to which of the following

Question

The function P(m) below relates the amount of time (measured in minutes) Jane spent on her homework and the number of problems completed.

It takes as input the number of minutes worked and returns as output the number of problems completed.



Which equation below represents the inverse function M(p), which takes the number of problems completed as input and returns the number of minutes worked?

Answer 1

Hi Beatriz,

 

To find the inverse function there are two steps.

 

1.  "Swap" x's and y's.  In your case, y=P(m), x=m.   So we will temporarily rewrite your function as y=x/5 +8   So when we re-write it with x's and y's swapped it will look like      x = y/5 + 8

 

2.  Solve for y.  (Isolate y).    x - 8 = y/5         5(x-8) = y     or    y=5x - 40

 

Now just put this back into your variables.   M(p) = 5p - 40