Question

Write series with summation notation with -1,2,-3,4,-5,6

Answer 1

hint:
first you want to find the common difference between the terms (ignoring the sign change). if you let the series start from n = 1, then how will you represent the series 1,2,3,4,5,6 using sigma notation?

then you want to write a part that will multiply odd (n) terms by -1 and even (n) terms by 1 (think about how you can achieve this by raising -1 to an exponent involving n)

finally, you will combine this information using sigma notation