\(lim\left(50.\dfrac{1-\left(\dfrac{4}{5}\right)^n}{1-\dfrac{4}{5}}+\dfrac{4}{5}.50.\dfrac{1-\left(\dfrac{4}{5}\right)^{n-1}}{1-\dfrac{4}{5}}\right)\) \(=50.\dfrac{1}{\dfrac{1}{5}}+\dfrac{4}{5}.50.\dfrac{1}{\dfrac{1}{5}}=450\)
1.lim(\(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+....+\frac{1}{n\left(n+1\right)}\))
2.Tìm tất cả các giá trị của a sao cho lim\(\frac{4^n+a.5^n}{\left(2a-1\right).5^n+2^n}\)=1
3. Cho \(a\in R\)và lim(\(\sqrt{n^2+an+4}-n+1=5\)).Tìm a
4.Cho\(Lim_{(x->2)}f\left(x\right)=5\). Tìm giới hạn \(lim_{\left(x->2\right)}\sqrt{[f\left(x\right)-3]x}\)
\(lim\frac{4^{n-1}+6^{n+2}}{5^n+2.7^n}\)
1) tính \(\lim\limits_{n\rightarrow\infty}\dfrac{6n-8}{n-1}\)
2) \(\lim\limits_{n\rightarrow\infty}\dfrac{n^2+5n-3}{4n^3-2n+5}\)
3) \(\lim\limits_{n\rightarrow\infty}\left(-2n^5+4x^4-3n^2+4\right)\)
1) tính \(\lim\limits_{n\rightarrow\infty}\dfrac{-6n^5+3n^3-1}{n^4-8n}\)
2) tính \(\lim\limits_{n\rightarrow\infty}\dfrac{-5n^7+8n^5-n}{5n^6-2n}\)
lim(√n+3-√n+5) lim 1/√n^2+2-√n^2+4 Giúp mk voiiiii
\(lim\frac{\left(n^4+n^2\right)^5.\left(2n^5+4\right)^2}{\left(n^3-n\right)^6.\left(4-2n\right)^6}\)
1) tính \(\lim\limits_{n\rightarrow\infty}\dfrac{3n^2+5n-3}{-n+5}\)
2) tính \(\lim\limits_{n\rightarrow\infty}\dfrac{-7n^2+4}{-n+5}\)
có \(ab=\frac{3}{5}\Leftrightarrow a=\frac{3}{5b}\)
có \(bc=\frac{4}{5}\Rightarrow c=\frac{4}{5b}\)
mà \(ac=\frac{4}{5}\Leftrightarrow\frac{3}{5b}.\frac{4}{5b}=\frac{3}{4}\Leftrightarrow\frac{12}{25.b^2}=\frac{3}{4}\Leftrightarrow12.4=3.25.b^2\)
\(\Leftrightarrow\frac{48}{75}=b^2\Leftrightarrow b^2=\frac{16}{25}\Leftrightarrow b=\pm\frac{4}{5}\)
với \(b=\frac{4}{5}\)thì \(a=3:\left(5.\frac{4}{5}\right)=3:4=\frac{3}{4}\)
\(c=4:\left(5.\frac{4}{5}\right)=4:4=1\)
với \(b=-\frac{4}{5}\)thì \(a=3:\left(5.\frac{-4}{5}\right)=3:-4=-\frac{3}{4}\)
\(c=4:\left(5.\frac{-4}{5}\right)=4:-4=-1\)
vậy \(\left(a;b;c\right)\in\left\{\left(\frac{4}{5};\frac{3}{4};1\right);\left(\frac{-4}{5};\frac{-3}{4};-1\right)\right\}\)
1) tính \(\lim\limits_{n\rightarrow\infty}\left(-2n^5+4x^4-3n^2+4\right)\)
2) tính \(\lim\limits_{n\rightarrow\infty}\dfrac{-3n^2+2}{n-2}\)
