Question

Range of f(x) = $\frac { e ^ { x } } { [ x + 1 ] }$, x ≥ 0 , where [.] denotes the greatest integer function, is

• A. (0, ∞)
• B. [0, ∞)
• C. (1, ∞)
• D. [1, ∞)

Answer 1

Answer: (D)

[1, ∞)

Answer 2

f(x) = , x > 0

⇒ f(x) = , I ≤ x < I +1

where I ∈ Integers and I ≤ 0

⇒ f(x) ∈ ∀ x ∈ [I, I + 1)

Thus range of f(x) is [1, ∞).