\(\lim\dfrac{2^{n}(4^{n+1}-3^{n+2}-1)}{5^{n}+8^{n}} =\lim\dfrac{4.8^{n}-9.6^{n}-2^{n}}{5^{n}+8^{n}} =\lim\dfrac{4-9.(\dfrac{6}{8})^{n}-(\dfrac{2}{8})^{n}}{(\dfrac{5}{8})^{n}+1} =\lim\dfrac{4-9.0-0}{0+1} =4\)
\(\lim\dfrac{2^{n}(4^{n+1}-3^{n+2}-1)}{5^{n}+8^{n}} =\lim\dfrac{4.8^{n}-9.6^{n}-2^{n}}{5^{n}+8^{n}} =\lim\dfrac{4-9.(\dfrac{6}{8})^{n}-(\dfrac{2}{8})^{n}}{(\dfrac{5}{8})^{n}+1} =\lim\dfrac{4-9.0-0}{0+1} =4\)
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) \(lim\dfrac{2n^3+n^2-3n+1}{2-3n}\)
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\(\dfrac{\left(-3\right)^n+5^n}{2.\left(-4\right)^n+5^n}\)
cho dãy số (un) có \(a=lim\left(1+\dfrac{-1}{2^n}\right)\). tìm gioi hạn \(lim\left(\dfrac{n^5}{n^4-2n^3+1}-an\right)\)
Tìm các giới hạn sau:
\(a,lim\dfrac{3+4^n}{1+3.4^{n+1}}\)
\(b,lim\dfrac{\left(-2\right)^n+3^n}{\left(-2\right)^{n+1}+3^{n+1}}\)
Tìm các giới hạn sau:
a) \(lim\left(4^n-3^n\right)\)
b) \(lim\left[\left(2^n+1\right)^2-4^n\right]\)
c) \(lim\left(\sqrt{2n^5-3n^2+11}-n^3\right)\)
d) \(lim\left(\sqrt{2n^2+1}-\sqrt{3n^2-1}\right)\)
e) \(lim\sqrt{n^2+3n\sqrt{n}+1}-n\)
Tìm các giới hạn sau:
\(a,lim\dfrac{\left(-3\right)^n-4.5^{n+1}}{2.4^n+3.5^n}\)
\(b,lim\dfrac{2^n-3^n+4.5^{n+2}}{2^{n+1}+3^{n+2}+5^{n+1}}\)
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) \(I=lim\left(\sqrt{2n^2+n}-\sqrt{n^2+2n+3}\right)\)