※ 引述《googoodoll (浮沉随浪．志气高)》之铭言： : lim ln(cos(2πx))/x^2 = ? : x→0 : thanks :D ln(cos(2πx)) lim --------------- x→0 x^2 ((2π)(-1)(sin(2πx))/(cos(2πx)) = lim ----------------------------------- x→0 2x sin(2πx) 1 = (-1)(2π)(lim -----------)(lim -----------) x→0 2x x→0 cos(2πx) sin(2πx) 1 = (-2π)(π)(lim -----------)(---) x→0 2πx 1 = (-2)(π^2)(1) = (-2)(π^2) --

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