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Let L = lim_{x->0} ( arcsin(x) / x )^(1/x^2). The value is L = e^a…

Question

Let L = lim_{x->0} ( arcsin(x) / x )^(1/x^2). The value is L = e^a for a rational a = m/n in lowest terms with m, n positive integers and gcd(m,n)=1. Find m + n.

✓ Verified answer: 7checked by our engine — not a guess

Step-by-step solution

Use arcsin(x) = x + x^3/6 + O(x^5), so arcsin(x)/x = 1 + x^2/6 + O(x^4).
Then ln( arcsin(x)/x ) = x^2/6 + O(x^4), and (1/x^2)·ln( arcsin(x)/x ) = 1/6 + O(x^2) -> 1/6.
Hence L = e^(1/6), so a = 1/6, m = 1, n = 6, and m + n = 7.

Final answer7

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