Proof
- Write x log x = log x ÷ (1/x), an ∞/∞ form.
- L'Hôpital: (1/x) ÷ (−1/x²) = −x.
- As x → 0⁺, −x → 0.
Standard limits
Questions students ask
What is the limit of x log x as x tends to 0⁺?
0.
How do you prove lim x→0⁺ x log x = 0?
Write x log x = log x ÷ (1/x), an ∞/∞ form. L'Hôpital: (1/x) ÷ (−1/x²) = −x. As x → 0⁺, −x → 0.