00:01
Okay, here in this case, the series is defined as summation i is equals to 1 to 7, okay, minus 1 raised to the, this is minus 1, right? so minus 1 raised to the power i plus 1 times i square.
00:14
So if i just open the summation sign, this simply groups like when you just put 1, okay, this is 1.
00:20
So when you put 1, this is 1 plus 1 2, right? so the concept which will be used in solidness question here is simply this, that minus 1 raise to the power odd number is negative and minus 1.
00:30
Minus 1 raised to the power even number is a positive value right so when you just put one this becomes even right one plus 1 is 2 so this is simply 1 square when you put 2 this is 2 plus 1 3 is a odd number right on putting 2 so this is simply minus 2 square then plus 3 square minus 4 square plus 5 square minus 6 is square right then plus 7 is where you can check it when you put i is equal to 7 so 7 plus 1 is 8 8 is positive that's why positive and this is 7 square.
01:01
So we just need to put all this value.
01:03
1 square is 1 minus 4 plus 9 minus 16 plus 25 minus 36 plus 49.
01:10
So add all the minus and add all the plus...