Part 1: Under certain conditions, functions can be invertible, 'undo-able'. That is, one function takes an input and through some sort of manipulation gives you an output - then the inverse function takes that output and turns it back into that exact input. The exponential and logarithmic functions behave like inverses of one another; you used this property when solving exponential and logarithmic equations. Can you think of any real-life procedures that behave in this way - i.e. are invertible? Or are NOT invertible. What are the special conditions that make a procedure invertible or not?

Part 2:Can you think of any real-life procedures that are 'almost' invertible, that is, are invertible after some adjustment or alteration?

Part 3:Can you think of any real-life procedures that can be made un-invertible, that is are un-invertible after some adjustment or alteration, but without change are perfectly invertible?