CMR:
a, 1.3.5...39/21.22.23...40=1/2mũ20
b, 1.3.5...(2n-1)/(n+1)(n+2)(n+3)...2n = 1/2mũn với n thuộc N*
Chứng minh rằng
1.3.5.........39/21.22.23......40=1/220
1.3.5...(2n-1)/(n+1).(n+2).(n+3)......2n=1/2n(biết n thuộc N*)
làm dc minh tk nha!
1. a) 1.3.5...39 / 21.22.23...40 = 1 / 220
b) 1.3.5...(2n + 1) / (n + 1)(n + 2) = 1 / 2n với n thuộc N*
Chứng minh rằng:
a)\(\frac{1.3.5...39}{21.22.23...40}=\frac{1}{2^{20}}\)
b)\(\frac{1.3.5...\left(2n-1\right)}{\left(n+1\right)\left(n+2\right)\left(n+3\right)...2n}=\frac{1}{2^n}\)với n thuộc N*
1)CMR:
a) \(\frac{1.3.5...39}{21.22.23...40}=\frac{1}{2^{20}}\)
b) \(\frac{1.3.5...\left(2n-1\right)}{\left(n+1\right).\left(n+2\right)\left(n+3\right)...2n}=\frac{1}{2^n}\)( n thuộc N* )
chung minh rag: a,1/2+1/2^2+1/2^3+,....+1/2^2016 <1 b,1.3.5.7.....39/21.22.23.....40=1/2^20 c,1.3.5.....(2n-1)/(n+1)(n+2)(n+3).....2n=1/2n
Chứng minh rằng:
1.3.5...39/21.22.23...40=1/2.2.2.2...2 (20 chữ số 2)
1.2.3...(2n-1)/(n+1)(n+2)(n+3)...2n=1/2.2 với n là phần tử của N*
Chứng minh rằng:
a) \(\frac{1.3.5...39}{21.22.23...40}=\frac{1}{2^{20}}\)
b)\(\frac{1.3.5...\left(2n-1\right)}{\left(n+1\right)\left(n+2\right)...2n}=\frac{1}{2^n}\)
C/M rằng
a) \(\frac{1.3.5.....39}{21.22.23.......40}=\frac{1}{2^{10}}\)
b) \(\frac{1.3.5.....\left(2n-1\right)}{\left(n+1\right).\left(n+2\right)......2n}=\frac{1}{2^2}\)