Grade 12Algebras=(3/1!+2!+3!)+(4/2!+3!+4!)+.............+(2008/2006!+2007!+2008!) then s is : A)1/2 - 1/2006! B)1/2 - 1/2008! c)1/2006! - 1/2008! D)1/2007! - 1/2008! shweta Kumari 15 Years agoGrade 12
Bharani VLSVSS15 Years agoAnswer is option b). The 'r' th term can be written as (r+2)/r!+(r+1)!+(r+2)! = (r+1)/(r+2)! = 1/(r+1)! - 1/(r+2)!. This sum can be telescoped(finite difference method) to get the required answer.