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Let f(x) = x/√(a² + x²) - (d - x)/√(b² + (d - x)²), x ∈ R, where a, b and d are non-zero real constants. Then: (1) f is an increasing function of x (2) f is neither increasing nor decreasing function of x (3) f' is not a continuous function of x (4) f is a decreasing function of x
- f is an increasing function of x
- f is neither increasing nor decreasing function of x
- f' is not a continuous function of x
- f is a decreasing function of x
Correct answer: f is an increasing function of x
Solution
The function f(x) is increasing because its derivative f'(x) is positive for all x in the real numbers, indicating that as x increases, f(x) also increases.
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