Find the values of x for which f(x) = log(1 + x) - 2x / (2 + x) is strictly increasing.

Find the values of x for which f(x) = log(1 + x) - 2x / (2 + x) is strictly increasing.

• A. x > -1
• B. x < -1
• C. x > 1
• D. x < 1

Answer: A) x > -1

Explanation: f'(x) = 1/(1+x) - [(2+x)2 - 2x(1)]/(2+x)² = x² / ((1+x)(2+x)²). For f'(x) > 0, x > -1 (and x ≠ 0). On its domain x > -1, it is strictly increasing.