sum of odd integers from 1 to 2001Find the sum of odd integers fi

1.	sum of odd integers from 1 to 2001Find the sum of odd integers fi
Answer» Integers from 1 to 2001 are 1,2,3,4,......2001 Odd integers from 1 to 2001 are 1,3,5,......1999,2001 this sequence forms an A.P as difference between the consecutive terms is constant. So the A.P is 1,3,5......1999,2001Here,First term = a = 1Common difference = d= 3-1= 2n=1001& last term = l = 2001 Sn=n/2(2a+(n-1)d)=1001/2(2×1+(1001-1)×2)=1002001

Answer»

Integers from 1 to 2001 are 1,2,3,4,......2001

Odd integers from 1 to 2001 are 1,3,5,......1999,2001

this sequence forms an A.P as difference between the consecutive terms is constant.

So the A.P is 1,3,5......1999,2001Here,First term = a = 1Common difference = d= 3-1= 2n=1001& last term = l = 2001

Sn=n/2(2a+(n-1)d)=1001/2(2×1+(1001-1)×2)=1002001

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