Cho A=1+1/2+1/3 +1/4+...+1/4030
B=1+1/3+1/5+1/7+...+1/4029
So sanh A/B với 4031/2016
Cho A=1+1/2+1/3 +1/4+...+1/4030
B=1+1/3+1/5+1/7+...+1/4029
So sanh A/B với 4031/2016
Cho A=1+1/2+1/3 +1/4+...+1/4030
B=1+1/3+1/5+1/7+...+1/4029
So sanh A/B với 4031/2016
cho A = 1+1/2+1/3+1/4+...+1/4030
B=1+1/3+1/5+...+1/4029
so sánh A/B với 4031/2016
cho A=\(\frac{1}{1+3}+\frac{1}{1+3+5}+...+\frac{1}{1+3+5+...+4031}\).so sanh A voi \(\frac{2015}{2016}\)
cho A=1+1/2+1/3+1/4+......+1/4026, B=1+1/3+1/5+1/7+...+1/4025 so sanh a/b voi1+2013/2014
Cmr:
A= \(\dfrac{3}{1^2×2^2}\)+\(\dfrac{5}{2^2×3^2}\)+\(\dfrac{7}{3^2×4^2}\)+...+\(\dfrac{4031}{2015^2×2016^2}\)<1
\(A=\dfrac{3}{1^2.2^2}+\dfrac{5}{2^2.3^2}+\dfrac{7}{3^2.4^2}+...+\dfrac{4031}{2015^2.2016^2}\)
\(A=\dfrac{2^2-1^2}{1^2.2^2}+\dfrac{3^2-2^2}{2^2.3^2}+\dfrac{4^2-3^2}{3^2.4^2}+...+\dfrac{2016^2-2015^2}{2015^2.2016^2}\)
\(A=1-\dfrac{1}{2^2}+\dfrac{1}{2^2}-\dfrac{1}{3^2}+\dfrac{1}{3^2}-\dfrac{1}{4^2}+...+\dfrac{1}{2015^2}-\dfrac{1}{2016^2}\)
\(A=1-\dfrac{1}{2016^2}< 1\left(đpcm\right)\)
cho A=1/1*2+1/3*4+...+1/99.100
B=7/2
C=5/6
so sanh A&B va so sanh A& C
so sanh A = a*b /a^2+b^2 va B = a^2+b^2/(a+b)^2
Câu 1
a) Chứng tỏ rằng 1/3 - 1/3^2 + 1/3^3 - 1/3^4 + 1/3^5 - 1/3^6 < 1/4
b) Cho A= 2015^2016 + 2016^2015 x 2015 và B= 1 + 2^2 + 3^2 + ......+2016^2. Tính AB có chia hết cho 5 không? Vì sao?
cho A= 1+1/2 +1/3 +.....+ 1/4029 +1/4030
và B= 1+1/3 =1/5 +1/7 +...+ 1/4027 + 1/4029
So sánh A/B với 1 2015 / 2016