Consider the function defined by

MATHEMATICS · Single correct · A Level · Mathematics · Algebra and Functions · Algebra and Functions

Problem

Consider the function

f_a:\mathbb R\setminus\{-1\}\to \mathbb R

defined by

f_a(x)=\dfrac{x-a}{x+1}

, where

a\in\mathbb R

. For which value(s) of

a

f_a

not invertible? (a)

a=0

(b)

a=-1

(c)

a=1

(d) Every real

a