reverse problem

A reverse problem is a problem where we have to return to the original value.

For example, if the length of a square is 6 cm, we can calculate the area of the square as 6 × 6 = 36 cm². The reverse problem in this case would be calculating the length of the square given that its area is 36 cm². The square root of 36 would have to be calculated to discover the original length, 6 cm.