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Limit of (sin x / x)^(1/x)
Short answer
Let L = lim_{x→0⁺} (sin x/x)^{1/x}. Take log: ln L = lim ln(sin x/x)/x. Using series or L'Hôpital, the limit is 0, so L = e⁰ = 1.
Evaluate lim_{x→0⁺} (sin x / x)^(1/x).
Let L = lim_{x→0⁺} (sin x / x)^(1/x). As x → 0, sin x / x → 1 and 1/x → ∞, so this is the form 1^∞.
Take logarithms:
ln L = lim_{x→0⁺} ln(sin x / x) / x = lim [ln sin x − ln x] / x (form 0/0)
Apply L'Hospital's rule:
ln L = lim [ cot x − 1/x ]
= lim (x cos x − sin x) / (x sin x) (0/0)
= lim (−x sin x) / (sin x + x cos x) (differentiate top and bottom)
= 0 / 0 → differentiate again:
lim (−sin x − x cos x) / (2 cos x − x sin x) = 0 / 2 = 0
Check by series: sin x / x = 1 − x²/6 + ..., so ln(sin x/x) ≈ −x²/6, and (−x²/6)/x = −x/6 → 0.
So ln L = 0.
Answer: L = e⁰ = 1.
✓ Answer checked by Claude Opus 5.5 (high effort)
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