Question

Find the 10th partial some of the sigma notation below?

Answer 1

I did the problem but I keep getting -244 and the options are
222
240
255
-355

Answer 2

its an arithmetic series
\[Sum = \frac{n(a_3 + a_{12})}{2} = \frac{10(-13 -58)}{2} = -355\]

Answer 3

Sorry if this is a silly question, but how come it's -58 and not -48 because I thought when you plug in 10 for i in -5i +2 you get -48? @dumbcow

Answer 4

not silly at all :)

the reason is that the sum starts at i=3 , instead of i=1 so 10 iterations from i=3 gives i=12
thus -58

Answer 5

oh okay thank you so much! @dumbcow