Inverse Function

b) (x-1)/x

it is x-1/x option (b).

calculation..given f(x)=1/1-x

write it in the form of equation by assuming f(X) as y

therefore y=1/1-x

x=(y-1)/y

i.e; ƒ⁻¹(y)= (y-1)/y

and hence ƒ⁻¹(x) = (x-1)/x is solution.

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

put,

y= 1/(1-x)

y(1-x) = 1

1-x = 1/y

1-(1/y) =x

(y-1)/y = x

ƒ⁻¹(x) = (x-1)/x

thanks a lot...