Find the sum of odd integers from 1 to 2001.
Answers
10,02,001
The odd integers from 1 to 2001 are in the form of an AP.
The First Term Of This AP (a) = 1
The Common Difference Of This AP (d) = 2
To Find:
The sum of odd integers from 1 to 2001.
Calculating:
First let us find the nth term of this AP.
To find the nth term of an AP we use the formula:
an = a + (n - 1) d
Substituting all the values we know into this formula we get:
2001 = 1 + (n - 1)(2)
Taking 1 to the other side of the equation we get:
2001 - 1 = (n - 1)(2)
2000 = (n - 1)(2)
Taking 2 to the other side of the equation we get:
2000 / 2 = n - 1
1000 = n - 1
Taking - 1 into the other side of the equation we get:
n = 1000 + 1
n = 1001
Therefore, the nth term of the AP is 1001.
Now we need to calculate the sum of odd integers from 1 to 2001. So we use the formula to calculate the sum of n terms.
The formula that is used to calculate the sum of n terms of an AP is:
Sn = n/2(2a + (n - 1) (d)
Substituting all the values known to us into this formula we get:
Sn = 1001/2 (2 x 1 + (1001 - 1) (2))
Sn = 1001/2 (2 + ((1000) (2))
Sn = 1001/2 (2 + 2000)
Sn = 1001/2 (2002)
Sn = 1001 x 1001
Sn = 10,02,001
Hence, the sum of odd integers from 1 to 2001 is 10,02,001.