Question

A = {-2,-1, 1, 2} and f = {(x,1/x); x ∈ A}. Write down the range of f. Is f a function from A to A?

Answer 1

Given, f = (x,1/x) ; So f(x) = 1/x

f (-2) = 1/-2 = –1/2 ; f(-1) = 1/-1 = -1

f(1) = 1/1 = 1 ; f(2) = 1/2 = 1/2 

Range of f = {-1/2, -1, 1, 1/2}

It is not a function from A to A since – 1/2, 1/2 ∈ A