A= (1-1/2)x(1-1/3)x(1-1/4)x.......x (1-1/2013)x(1-1/2014)=?
Những câu hỏi liên quan
a, x+1/2013+x+1/2014+x+1/2015=x+1/2016+x+1/2017
b,x-1/2013+x-2/2014+x-3/2015=x-4/2016-2
A= (1-1/2)x(1-1/3)x(1-1/4)x.........x(1-1/2013)x(1-1/2014)
\(A=\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x......x\left(1-\frac{1}{2013}\right)x\left(1-\frac{1}{2014}\right)\)
\(A=\frac{1}{2}x\frac{2}{3}x\frac{3}{4}x...............x\frac{2012}{2013}x\frac{2013}{2014}\)
\(A=\frac{1}{2014}\)
Đúng 0
Bình luận (0)
\(\left[1-\frac{1}{2}\right]\left[1-\frac{1}{3}\right]...\left[1-\frac{1}{2014}\right]\)
\(=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}...\cdot\frac{2013}{2014}\)
\(=\frac{1\cdot2\cdot3\cdot...\cdot2013}{2\cdot3\cdot4\cdot5\cdot...\cdot2014}=\frac{1}{2014}\)
Đúng 0
Bình luận (0)
Mình ko viết lại đề nữa nha
A= 1/2 x 2/3 x 3/4 x ...........x 2012/2013 x 2013/2014 (loại bỏ những số giống nhau)
A= 1/2014
Đúng 0
Bình luận (0)
Xem thêm câu trả lời
Tính A = ( 1- 1/2 ) x ( 1 - 1/3 ) x ( 1 - 1/4 ) x ... x ( 1 - 1/2013 ) x ( 1- 1/2014 )
A=(1-1/2)x(1-1/3)x(1-1/4)x....x(1-1/2013)x(1-1/2014) .Vay A la
A=1/2*2/3*3/4*...*2012/2013*2013/2014
Ta gạch bỏ các chữ số giống nhau còn lại 1/2014
Vậy A= 1/2014
Đúng 0
Bình luận (0)
E=(1/1/2.xy^2)(1/1/3.x^2.y^3)(1/1/4.x^3.y^4).....(1/1/2014.x^2013.y^2014)
tìm x biết (1/2 + 1/3 + 1/4 + .... + 1/2014 ) . x = 2013/1 + 2012/2 + ...+ 1/2013
a)S = 1 + 1/3 + 1/9 + 1/27 + ..................... + 1/2187
b)S = 1 + 1/2 + 1/4 + 1/8 + ..................... + 1/128 + 1/256
c)A = 1 + 2 + 4 + 8 + ..................... + 4096 + 8192
d)1/1 x2 + 1/ 2 x 3 + 1/ 3 x 4 + ................. + 1/ 2013 x 2014
h)A = 1/1 x3 + 1/ 3 x 5 + 1/ 5 x 7 + ................. + 1/ 2013 x 2015
bai2a)1/ 2 x (1 + 2) + 1/ 2 x (1 + 2 + 3) + ............ + 1/2 x (1 + 2 + 3 + ....... + 9)
ai nhanh tick đúng nha
\(a)\) \(S=1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+...+\frac{1}{2187}\)
\(S=1+\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+...+\frac{1}{3^7}\)
\(3S=3+1+\frac{1}{3}+\frac{1}{3^2}+...+\frac{1}{3^6}\)
\(3S-S=\left(3+1+\frac{1}{3}+\frac{1}{3^2}+...+\frac{1}{3^6}\right)-\left(1+\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+...+\frac{1}{3^7}\right)\)
\(2S=3+\frac{1}{3^7}\)
\(2S=\frac{3^8+1}{3^7}\)
\(S=\frac{3^8+1}{3^7}.\frac{1}{2}\)
\(S=\frac{3^8+1}{2.3^7}\)
Vậy \(S=\frac{3^8+1}{2.3^7}\)
Chúc bạn học tốt ~
Đúng 0
Bình luận (0)
trả lời giúp mik câu hỏi này nhé
A = ( 1 - 1/2 ) x ( 1 - 1/3 ) x ( 1 - 1/4 ) x...... x ( 1 - 1/2013 ) - ( 1 - 1/2014 )
Cho A=(1/2^2-1)x(1/3^2-1)x(1/4^2-1)...(1/2013^2-1)x(1/2014^2-1) và B=-1/2.so sánh A và B
\(A=\left(\frac{1}{2^2}-1\right)\left(\frac{1}{3^2}-1\right)\left(\frac{1}{4^2}-1\right)...\left(\frac{1}{2014^2}-1\right)\)
\(-A=\left(1-\frac{1}{2^2}\right)\left(1-\frac{1}{3^2}\right)\left(1-\frac{1}{4^2}\right)...\left(1-\frac{1}{2014^2}\right)\)
\(-A=\frac{3}{2\cdot2}\cdot\frac{8}{3\cdot3}\cdot\frac{15}{4\cdot4}\cdot...\cdot\frac{4056195}{2014\cdot2014}\)
\(-A=\frac{\left(1\cdot3\right)\left(2\cdot4\right)\left(3\cdot5\right)...\left(2013\cdot2015\right)}{\left(2\cdot2\right)\left(3\cdot3\right)\left(4\cdot4\right)...\left(2014\cdot2014\right)}\)
\(-A=\frac{\left(1\cdot2\cdot3\cdot...\cdot2013\right)\left(3\cdot4\cdot5\cdot...\cdot2015\right)}{\left(2\cdot3\cdot4\cdot...\cdot2014\right)\left(2\cdot3\cdot4\cdot...\cdot2014\right)}\)
\(-A=\frac{1\cdot2015}{2014\cdot2}=\frac{2015}{4028}\)
\(A=\frac{-2015}{4028}\)
Đúng 0
Bình luận (0)