Seven cookies of radius $1$ inch are cut from a circle of cookie dough, as shown. Neighboring cookies are tangent, and all excep
t the center cookie are tangent to the edge of the dough. The leftover scrap is reshaped to form another cookie of the same thickness. What is the radius in inches of the scrap cookie?
Because they're not inverses, not exactly. is not invertible on its entire domain because it's not one-to-one. There are infinitely many values of such that , for example.
The standard function has a domain of and outputs values between and . This means that its inverse, , is indeed its inverse as long as .
is larger than and thus does not fall in the "invertible part" of the domain of . We have
which is a value between -1 and 1, so that
If we wanted to recover , we'd have to redefine or define a new inverse function that works on a different branch of the domain of .