Help me find fx from gx,f(fx) ?

Find fx from gx and f(gx)

Ex:

find f(1/2) with gx=1-x^2 and f(gx)=(x^4+x^2)/(1+x^2)

syms x;
a=input(' a= ');
g=input(' gx= ');
f=input(' fx = ');

...?????? I don't know...please help me ! Thanks a lot!

Answer 1

[bym]

here is a start

clc;clear
syms x
gx = input('gx = ','s');
fx = input('f(gx) = ','s');
a = input('f(n) = ','s');  % 1/2 in your example

n = solve([gx '-' a],'x')

% f(1/2) = ? for you to complete
doc subs