Is there any straightforward way to calculate inverse of a function in sage? For example:
f(x) = 2 * x - 1
f^-1(x) = ( x + 3 ) / 2
I have encountered solutions like this. But this was answered 9 years ago, I hope there exist a better way to do now.
This cas is especially simple:
sage: f(x)=2*x-1
sage: var("y")
y
sage: solve(f(x)==y,x)
[x == 1/2*y + 1/2]
sage: f_1(y)=solve(f(x)==y,x)[0]; f_1
y |--> x == 1/2*y + 1/2
Other cases may be more problematic (the equation may have more than one solution, or no solution at all, or sotutions that solve isn't able to find). But this is a start.
Asked: 2020-03-09 15:50:35 +0100
Seen: 1,220 times
Last updated: Mar 11 '20
Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.