Question

The interval in which the function f(x) = xe^4–x decreases is –

• A. (–¥, 1)
• B. (1, ¥)
• C. (0, 4)
• D. None of these

Answer 1

Answer: (B)

(1, ¥)

Answer 2

f(x) = x . e^4–x ¯

f '(x) = – x. e^{4– x} + e^{4 –x}

f '(x) = – e^{4 – x}(x – 1) < 0

f '(x) :