Question

If f(x) = (x+1)/(x-1) , show that f[f(x)] = x.

Answer 1

Answer:

f[f(x)] = x

Step-by-step explanation:

f(x) = x+1/x-1

f[f(x)] =f[x+1/x-1]

=(x+1)/x-1)+1÷(x+1/x-1)-1

=x+1+x-1/x-1÷x+1-x+1/x-1

=2x÷2

=x

therefore f[f(x)]=x proved