Tìm các giới hạn sau:
a)\(lim\left[n^2\left(\sqrt{n^2+2}-\sqrt{n^2+4}\right)\right]\)
b)lim( \(\dfrac{3}{n-2}-5n\))
c) lim(\(\dfrac{n-1}{\sqrt{3}-n}-\dfrac{4}{2^{-n}}\))
d) \(lim\left(\dfrac{n^2-4}{n-2}-\dfrac{3n^2+4}{n}\right)\)
e) \(lim\dfrac{\sqrt{n^2+1}-n\sqrt{5}}{\sqrt{n^2+1}+n\sqrt{5}}\)
Tìm các giới hạn sau:
a) \(lim\sqrt[3]{-n^3+2n^2-5}\)
b) \(lim\dfrac{1}{\sqrt{n+1}-\sqrt{n}}\)
c) \(lim\left(\dfrac{1}{n+1}-n\right)\)
d) \(lim\left(\dfrac{2n^2-1}{n+1}-2n\right)\)
e) \(lim\dfrac{2n^3+n^2-3n+1}{2-3n}\)
Tính:
A= \(lim\dfrac{n+1}{n^2+2n}\)
B= \(lim\left(-2n^3+n^2+2\right)\)
C= \(lim\dfrac{\sqrt{9n^2-n-1}}{4n-2}\)
D= \(lim\dfrac{3^n+5.4^n}{4^n+2^n}\)
Tìm giới hạn dãy số :
\(a,lim\dfrac{5n+1}{2n}\\ b,lim\dfrac{6n^2+8n+1}{5n^2+3}\\ c,lim\dfrac{3^n+2^n}{4.3^n}\\ d,lim\dfrac{\sqrt{n^2+5n+3}}{6n+2}\)
tính các giới hạn sau:
a) lim (3n2+n2-1)
b)lim \(\dfrac{n^3+3n+1}{2n-n^3}\)
c) lim \(\dfrac{-2n^3+3n+1}{n-n^2}\)
d) lim \(\left(n+\sqrt{n^2-2n}\right)\)
e) lim \(\left(2n-3.2^n+1\right)\)
f) lim \(\left(\sqrt{4n^2-n}-2n\right)\)
g) lim \(\left(\sqrt{n^2+3n-1}-\sqrt[3]{n^3-n}\right)\)
Tính các giới hạn sau
1,Lim\(\left(\dfrac{2n^3}{2n^2+3}+\dfrac{1-5n^2}{5n+1}\right)\)
2,a,Lim\(\left(\sqrt{n^2+n}-\sqrt{n^2+2}\right)\)
b,Lim\(\dfrac{\sqrt{n^4+3n-2}}{2n^2-n+3}\)
c,Lim\(\dfrac{\sqrt{n^2-4n}-\sqrt{4n^2+1}}{\sqrt{3n^2+1}-n}\)
Tính:
a) \(I=lim\dfrac{5^n+2^n}{3^n+4^n}\)
b) \(I=lim\dfrac{\sqrt{n^3+2n}+3n}{n+\sqrt{n^2+1}}\)
c) \(I=lim\left(\sqrt{2n^2+n}-\sqrt{n^2+2n+3}\right)\)
Tính các giới hạn sau:
a) \(\lim\limits\dfrac{\sqrt[3]{n^6-7n^3-5n+8}}{n+12}\)
b) \(\lim\limits\dfrac{1}{\sqrt{3n+2}-\sqrt{2n+1}}\)
c) \(\lim\limits\dfrac{4.3^n+7^{n+1}}{2.5^n+7^n}\)
a,CMR :dãy u(n)=\(\left(1+\dfrac{1}{n}\right)^n\)có giới hạ hữu hạn
b đặt lim(1+\(\dfrac{1}{n}\))^n =e .Tính các giưới hạn sau ; lim\(\left(\dfrac{n+1}{n-1}\right)^{n+2}\)và lim\(\left(\dfrac{n-2}{n+3}\right)^{n+1}\)
1. lim\(\dfrac{\left(n+2\right)^{50}.\left(n-3\right)^{80}}{\left(2n-1\right)^{40}.\left(3n-2\right)^{45}}\)
2. lim\(\dfrac{4^n}{2.3^n+4^n}\)
3. lim\(\dfrac{3^n-2.5^n}{7+3.5^n}\)
4. lim\(\dfrac{4^n-5^n}{2^{2n}+3.5^{2n}}\)
5. lim\(\dfrac{\left(-3\right)^n+5^n}{2.\left(-4\right)^n+5^n}\)