MATLAB: How to expose a symbol from an equation? I have Symbolic Math Toolbox, if it is necessary

Question

Let say I have an equation like:

 y = @(x) x^2 + 2;

I want to express X in dependence of Y like:

 x = @(y) sqrt(y-2);

Answer 1

You have to set a few rules for the Symbolic Math Toolbox, but this is one possibility:

syms x y positive
assume(y > 2)
Eqn = y == x^2 + 2;
x = solve(Eqn)
x =
(y - 2)^(1/2)

EDIT — If you want to create an anonymous function from ‘x’, use the matlabFunction function.