1, - 3.5, - 7.9,11, - 13 So what's the 100th number in this column?

1, - 3.5, - 7.9,11, - 13 So what's the 100th number in this column?

The sign is positive and negative
So the 100th symbol is the same as the second one-
Don't look at symbols
It's 1, 3, 5, 7
Is an odd number, denoted by 2N-1
The 100th odd number is 2 × 100-1 = 199
So the 100th is - 199

One column number 1, one 3, 5, one 7, 9, 11, one 13 So the 100th number in this column is

X=(-1)^n*(2n-1)
Therefore, the 100th = 199

A column of numbers 1, - 3,5, - 7,9,11, - 13. What is the hundredth number?

The nth number is - 1 ^ (n + 1) * (2n-1)
The hundredth number is: (- 1) ^ (100 + 1) * (200-1) = - 199