Solveeit Logo

Question

Question: \(\int_{0}^{\infty}{}\) [2 e<sup>-x</sup>]dx, where [.] denotes the greatest integer function, is eq...

0\int_{0}^{\infty}{} [2 e-x]dx, where [.] denotes the greatest integer function, is equal to

A

0

B

ln 2

C

e2

D

2e–1

Answer

ln 2

Explanation

Solution

Since 0 < 2 e–x ≤ 2 ∀ x ∈ [0, ∞),

[2 e–x] = 0, for x > ln2.

Hence the given integral =0ln2dx\int_{0}^{ln2}{dx}+ 0 = ln 2