00:01
Okay, here in this case we just need to find the sum of integers from minus 100 to 30.
00:05
So this is minus 100 plus minus 99.
00:09
We just need to add in this way.
00:11
Minus 100, minus 99, then minus 98.
00:14
Then at some time it will reach to 0, then 1, then 2, then then finally it is plus of 30.
00:20
We just need to add this value here.
00:23
Alright, so quite simple question.
00:26
We will first add the negative side and then we will add the positive side.
00:29
If i add the negative side, this something looks like this.
00:31
If i take minus common, this is 100, 99, 98, right? and way up to 0.
00:38
Then if i add the positive side, this is 1 plus 2, plus 3, then finally plus 30.
00:43
So we will be simply using this formula here that summation of n is equal to n into n plus 1 by 2, right? the sum of first n natural number.
00:51
Okay, so you can see this, this is 1, 2, 4 till 100 in here and this is 1 2, i mean this is from 1 2 till 30.
01:00
So we will be applying this formula twice...