Tìm A =(2004+2003/2+2002/3+...+1/2004) : ( 1/2+1/3+1/4+1/5+...+1/2005)
Tìm A =(2004+2003/2+2002/3+...+1/2004) : ( 1/2+1/3+1/4+1/5+...+1/2005)
B=(1-1/2)*(1-1/3)*(1-1/4)*(1-1/5)*.....*(1-1/2003)*(1-1/2004)
1, tính nhanh:
(1-1/2) *(1-1/3) *(1-1/4)* (1-1/5)*......*(1-1/2003)*(1-1/2004)
b = ( 1- 1/2 ) * (1- 1/3) * (1- 1/4) * (1- 1/5) * ......... * (1- 1/2003) * (1- 1/2004) = ?
Tính :
( 1-1/2 ) * ( 1-1/3 ) * ( 1-1/4 ) * ( 1-1/5 ) * ..... * ( 1 -1/2003 ) * ( 1-1/2004 )
(1-1/2)x(1-1/3)x(1-1/4)x(1-1/5)x...x(1-1/2003)x(1-1/2004)
Tính giá trị biểu thức
B = ( 1 - 1/2 ) x ( 1 - 1/3 ) x ( 1 - 1/4 ) x ( 1 - 1/5 )....( 1 - 1/2003 ) x ( 1 - 1/2004 )
A=(1-1/2)*(1-1/3)*(1-1/3)*(1-1/4)*(1-1/5)* ... * (1-1/2003)*(1-1/2004)
/ : Là phân số