d = (r ^ 2)/24 The function is a model for the distance d in feet that a car with locked brakes skids when coming to a complete stop from a speed of mi / h * r . Find the inverse of the function. Use the inverse to estimate the speed of a car that made skid marks 136 feet long.

One way to understand division is to look at it as repeated
subtraction.  When you "divide by" a divisor number, you're
asking "how many times can I subtract this divisor from the
dividend, before the dividend is all used up ?".

Well, if the divisor is ' 1 ', then you're taking ' 1 ' away from the
dividend each time, and the number of times will be exactly
the same as the dividend.

If the divisor is more than ' 1 ', then you subtract more than ' 1 '
from the dividend each time, and the number of times you can
do that is less than the dividend itself.

If the divisor is less than ' 1 ', then you only take away a piece of
' 1 ' each time.  You can do that more times than the number in
the dividend, because you only take away a piece each time.