A jogger is running around an athletics track. The stopwatch says 1 minute 20 seconds after the first lap, and 3 minutes 10 seconds after the second. How long did it take the jogger to complete the second lap?

the answer is b ) square root of 5

we have been given a quadratic function and we need to restrict the domain such that it becomes a one to one function.

we know that vertex of this quadratic function occurs at (5,2).

further, we know that range of this function is .

if we restrict the domain of this function to either or , it will become one to one function.

let us know find its inverse.

upon interchanging x and y, we get:

let us now solve this function for y.

hence, the inverse function would be if we restrict the domain of original function to and the inverse function would be if we restrict the domain to .