# Need a complete list of functions and thier inverses

by Jeff12341234
Tags: functions, inverses, list, thier
 P: 179 I can't find this anywhere on google. I'm looking for a complete list of functions and their inverses. Here's a partial list as an example *, / +, - e^x, ln(x) sin(), sin^-1() d/dx, ∫ etc.. Why isn't there a list of all of them? You would think that some mathematician would find joy in compiling one...
 P: 784 Assuming......just assuming.......that you aren't trolling. There are an infinite amount of functions, and I'm going to take a gander and say that the vast majority of them do not have inverses. There are, however, a relativity short list of 'common' functions, and I'm sure it is very easy to google a list of their inverses, though you've listed a number already. I'll stress here that neither ##\frac{d}{dx}## nor ##\int## are functions, though they are inverse operations. Nor are multiplication, division, addition or subtraction, they are all operations.
 Mentor P: 18,346 There are $2^{2^{\aleph_0}}$ functions from $\mathbb{R}\rightarrow \mathbb{R}$ This means that the number of functions from $\mathbb{R}$ to $\mathbb{R}$ is not only infinite, but a number of degrees above the smallest possible infinity. Thus, I fear that a complete list of functions would not be very feasible. If you want a list of all possible function between all possible sets. Then I'm afraid that they don't even form a set. The number of functions form a proper class. This means that is quite larger than anything mathematics can handle. So a list would be rather impossible.
Mentor
P: 18,346
Need a complete list of functions and thier inverses

 Quote by Vorde I'll stress here that neither ##\frac{d}{dx}## nor ##\int## are functions, though they are inverse operations. Nor are multiplication, division, addition or subtraction, they are all operations.
I would actually consider all those things as functions...
P: 179
 Quote by Vorde Assuming......just assuming.......that you aren't trolling. I'll stress here that neither ##\frac{d}{dx}## nor ##\int## are functions, though they are inverse operations. Nor are multiplication, division, addition or subtraction, they are all operations.
ok. then what I'm looking for is a complete list of opposite operations.
Mentor
P: 18,346
 Quote by Jeff12341234 ok. then what I'm looking for is a complete list of opposite operations.
Still too large (= infinity).
 P: 179 no it's not. There are a few dozen we learn in algebra, another dozen from trig, only 2 from calc (d/dx and ∫ ), diff eq may add more to the list but I didn't notice any. you see? Get real. The question is not that hard. A list of opposite functions would be handy to have when solving for a variable in a complex algebraic equation.
Mentor
P: 18,346
 Quote by Jeff12341234 no it's not. There are a few dozen we learn in algebra, another dozen from trig, only 2 from calc (d/dx and ∫ ), diff eq may add more to the list but I didn't notice any. you see? Get real. The question is not that hard
So, you are saying that there are only a finite number of bijective functions in existence? Do you have any proof/evidence for that?
 Mentor P: 18,346 Anyway, the OP is just a troll, so I'm locking this.

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