Question

高数求极限问题？

如何由二阶求到得到那个结论

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Answer 1

lim<x→0>f(x)/(1-cosx) = lim<x→0>f(x)/(x^2/2) = 2lim<x→0>f(x)/x^2 = A,
则 lim<x→0>f(x)/x^2 = A/2.
J = lim<x→0>∫<下0, 上x>tf(x^2-t^2)dt/x^6
= lim<x→0> -(1/2) ∫<下0, 上x> f(x^2-t^2)d(x^2-t^2)/x^6
令 x^2-t^2 = u,
J = lim<x→0> -(1/2) ∫<下x^2, 上0> f(u)du/x^6
= lim<x→0> (1/2) ∫<下0, 上x^2> f(u)du/x^6 (0/0)
= lim<x→0> (1/2) 2xf(x^2)/(6x^5) = lim<x→0> f(x^2)/(6x^4)
令 x^2 = v, 则
J = (1/6) lim<v→0> f(v)/v^2 = (1/6)A/2 = A/12

Answer 2

高数的极限问题就是太多了一天碰到几十个都是高数微积分问答

Answer 3

毕业时间太长了，高数全都忘了，做不出来