Chứng minh M thuộc tập số nguyên, biết M = \(\dfrac{1}{3}\) + \(\dfrac{2}{3^2}\) + \(\dfrac{3}{3^3}\) + ... + \(\dfrac{2024}{3^{2024}}\)
Những câu hỏi liên quan
\(\dfrac{2^{2023}+3^{2023}}{2^{2024}+3^{2024}}\) chứng minh phấn số đó tối giản
A = \(\dfrac{1}{3}\)-\(\dfrac{2}{^{ }3^2}\)+\(\dfrac{3}{3^3}\)-\(\dfrac{4}{3^4}\)+...+\(\dfrac{2023}{3^{2023}}\)-\(\dfrac{2024}{3^{2024}}\) so sánh A với \(\dfrac{3}{16}\)
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Tính: \(S=C^0_{2024}+\dfrac{1}{2}.C^2_{2024}+\dfrac{1}{3}.C^4_{2024}+\dfrac{1}{4}.C^6_{2024}+...+\dfrac{1}{1013}.C^{2024}_{2024}\)
Tính: \(S=C^0_{2024}+\dfrac{1}{2}.C^2_{2024}+\dfrac{1}{3}.C^4_{2024}+\dfrac{1}{4}.C^6_{2024}+...+\dfrac{1}{1013}.C^{2024}_{2024}\)
Tính: \(S=C^0_{2024}+\dfrac{1}{2}.C^2_{2024}+\dfrac{1}{3}.C^4_{2024}+\dfrac{1}{4}.C^6_{2024}+...+\dfrac{1}{1013}.C^{2024}_{2024}\)
\(S=C^0_{2024}+\dfrac{1}{2}C^2_{2024}+\dfrac{1}{3}C^4_{2024}+\dfrac{1}{4}C^6_{2024}+...+\dfrac{1}{1013}C^{2024}_{2024}\)
Ta có :
\(\dfrac{1}{k+1}C^{2k-1}_n=\dfrac{1}{k+1}.\dfrac{n!}{\left(2k-1\right)!\left(n-2k+1\right)!}\)
\(=\dfrac{1}{n+1}.\dfrac{\left(n+1\right)!}{2k!\left[\left(n+1\right)-2k\right]!}\)
\(=\dfrac{1}{n+1}C^{2k}_{n+1}\)
\(\Rightarrow S_n=\dfrac{1}{n+1}\Sigma^{2k}_{k=0}C^{2k}_{n+1}=\dfrac{1}{n+1}\left(\Sigma^{2k}_{k=0}C^{2k-1}_{n+1}-C^0_{n+1}\right)=\dfrac{2^{2n-1}-1}{n+1}\)
\(\Rightarrow S=\dfrac{2^{2025}-1}{1013}\)
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Tính: \(S=C^0_{2024}+\dfrac{1}{2}.C^2_{2024}+\dfrac{1}{3}.C^4_{2024}+\dfrac{1}{4}.C^6_{2024}+...+\dfrac{1}{1013}.C^{2024}_{2024}\)
S = C₀₂₀₂₄ + 12.C₂₀₂₄ + 13.C₂₀₂₄ + 14.C₂₀₂₄ + ... + 11013.C₂₀₂₄
= (C₀₂₀₂₄ + C₂₀₂₄ + C₂₀₂₄ + C₂₀₂₄ + ... + C₂₀₂₄) + (C₂₀₂₄ + C₂₀₂₄ + C₂₀₂₄ + ... + C₂₀₂₄) + ... + (C₂₀₂₄)
= 11014.C₂₀₂₄
= 11014.
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Tính: \(S=C^0_{2024}+\dfrac{1}{2}.C^2_{2024}+\dfrac{1}{3}.C^4_{2024}+\dfrac{1}{4}.C^6_{2024}+...+\dfrac{1}{1013}.C^{2024}_{2024}\)
Tính: \(S=C^0_{2024}+\dfrac{1}{2}.C^2_{2024}+\dfrac{1}{3}.C^4_{2024}+\dfrac{1}{4}.C^6_{2024}+...+\dfrac{1}{1013}.C^{2024}_{2024}\)
Tính: \(S=C^0_{2024}+\dfrac{1}{2}.C^2_{2024}+\dfrac{1}{3}.C^4_{2024}+\dfrac{1}{4}.C^6_{2024}+...+\dfrac{1}{1013}.C^{2024}_{2024}\)