Find inverse values of functions

The  exercise appears under the Algebra II Math Mission. This exercise practices evaluating the inverse function of a function that is given either as a formula, or as a graph, or as a table of values.

Types of problems
There are two types of problems in this exercise:
 * 1) Drag the endpoints of the segment below to graph ___.: This problem explains that the graph of ___  is a line segment joining the points ___ and ___. User is then asked to drag the endpoints of the segment below to graph ___.
 * 2) What is the value of ___?: This problem has a graph of an invertible function on a grid below and user is asked to find what the value of ___ is. $$f$$

Strategies
Basic knowledge of functions is required for this exercise.
 * 1) Every linear function's inverse is also linear.
 * 2) By the definition of inverse functions, $$f^{-1}(x)=y$$ if and only if $$f(y)=x$$.