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Limx / (- x + x), when x tends to zero, does the limit exist? If it exists, what is it? If not, why not?
Because the denominator is always 0 (- x + x = 0), the fraction is meaningless, so the limit is meaningless and does not exist
How to prove Heine's theorem?
When I was working on the problem yesterday, I suddenly remembered that there was a theorem that had not been proved. Alas, I was uncomfortable. Who would help me
Don't go to Baidu Encyclopedia to test me a lot, what I want is specific steps
lim[x->a]f(x)=b ==> lim[n->∞]f(an)=b
If e > 0, there exists d > 0, if | x-a | a] f (x) is not b,
For any d > 0, there exists an X: satisfying | x-a | E
Then the contradiction is deduced by using the definition of sequence limit of LIM [n - > ∞] f (an) = B
(when you see here, you have enough ability to complete the later proof)
By Lagrange theorem, for any x, θ (- 1,1) arcsin x = x / radical (1 - θ ^ 2x ^ 2), it is proved that limx -- > 0, θ = 1 / radical 3
Unfold the left side
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