(50g) Inverse Function
02-05-2020, 03:17 PM (This post was last modified: 02-05-2020 03:25 PM by peacecalc.)
Post: #4
 peacecalc Member Posts: 187 Joined: Dec 2013
RE: (50g) Inverse Function
Hello,

@Albert Chan: I know of the geometrical work around, but of course the more interesting question is to find the inverse of a function with the calc, numerical better then nothing. The official handbooks even shows a program "ROOTR" which works in the same way, but with three variables (name of inverting function, name of solving variable and starting value).

In a more exact view, the mirrored graphing is dued to the change of the variables after the algebraic inverting procedures:

f. example:

1) y = x^2 + 16; with x in IR and y in [16 ; + infinity[
2) x_1 = sqrt(y - 16) and x_2 = - sqrt(y-16);
with y in [16 ; + infinity[ and x_1 in [0; + infinity[ and x_2 in ] - infinity; 0[
Here is the graph the same as in 1) you only changed the direction of view in the graph (in 1) x -> y and in 2) y -> x), nothing else. More precisely, x_1 is the domain of the right part of the graph and x_2 marks the left part.
3) Now you change x_1 to y_1 and x_2 to y_2 and y becomes x, voila the graph changes.

@Joe Horn, thank you, you beat me in reaction.

Sincerely peacecalc
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 Messages In This Thread (50g) Inverse Function - peacecalc - 02-05-2020, 08:43 AM RE: (50g) Inverse Function - Albert Chan - 02-05-2020, 11:03 AM RE: (50g) Inverse Function - Joe Horn - 02-05-2020, 01:09 PM RE: (50g) Inverse Function - peacecalc - 02-05-2020 03:17 PM RE: (50g) Inverse Function - peacecalc - 02-05-2020, 06:47 PM

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