Cho A= (1/2^2 - 1) (1/3^2 - 1) (1/4^2 - 1) ...(1/100^2 - 1)
So sánh A với -1/2
Cho A= (1/2^2 - 1) (1/3^2 - 1) (1/4^2 - 1) ...(1/100^2 - 1)
So sánh A với -1/2
viết gọn: 3*(2^2+1)*(2^4+1)*(2^8+1)*(2^16+1)*(2x+1)^2+(3-2x)^2+2*(2x+1)*(3-2x)
CM
\(S=\dfrac{1}{2^2}-\dfrac{1}{2^4}-\dfrac{1}{2^6}-...+\dfrac{1}{2^{4n-2}}-\dfrac{1}{2^{4n}}+...+\dfrac{1}{2^{2002}}-\dfrac{1}{2^{2004}}< 0,2\)
Cho:P =(1-1/1+2)(1-1/1+2+3)(1-1/1+2+3+4)...(1-1/1+2+3+...+2014). Tính: 2014/2016P
Tính các tổng sau:
a) A=\(\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{100}}\)
b) B=\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{102^2}\)
c) C=\(\dfrac{3}{1+2}+\dfrac{3}{1+2+3}+\dfrac{3}{1+2+3+4}+...+\dfrac{3}{1+2+3+...+100}\)
Tìm x
a) -3 ( 2/5x - 1/5) - x(x - 1/2) = 1/6 - x²
b) (2x - 1/2).2 + (1/2 + 1/3 +1/4): 1/8 = 1
c) 3| x -1/2| - 1 = 7
tính tổng 1/2 x ( 1+ 2) + 1/3x( 1+ 2+3) + 1/4 x ( 1+ 2+ 3+ 4) + ...+ 1/100x (n 1+ 2+ 3+ 4+ 5+ ....+ 100)
Cho E=(1-1/1+2)(1-1/1+2+3)(1-1/1+2+3)...(1-1/1+2+3+...+n)
và F=n+2/n với n thuộc N* .Tính E/F
Bài 1 : Tính : C = 1 + 1/2 ( 1 + 2 ) + 1/3 ( 1+2+3) +... + 1/16 (1+2+3+...+16 )