Question

Let f : R ➝ R be defined by f(x) = 1 – |x|. Then the range of f is …..

(a) R 

(b) (1, ∞) 

(c) (-1, ∞) 

(d) (-∞, 1]

Answer 1

(d) (-∞, 1]

f: R ➝ R defined by 

f(x) = 1 – |x| 

For example, 

f(1) = 1 – 1 = 0 

f(8) = 1 – 8 = -1 

f(-9) = 1 – 9 = -8 

f(-0.2) = 1 – 0.2 = 0.8 

so range = (-∞, 1]