Question

Write the sum using summation notation, assuming the suggested pattern continues.

-9 - 3 + 3 + 9 + ... + 81

Answer 1

what is the pattern you see?

Answer 2

I can't seem to see any.

Answer 3

adding 6

Answer 4

:O now I see it lol. I was thinking harder than I needed to lol

Answer 5

so the answer would be

Answer 6

instead of that 15 would it be infinity?

Answer 7

heheh summations are meant to look difficult but i've always found them fun and easy!

Answer 8

well, you are stopping at 81?

Answer 9

oh so it would be 15.

Answer 10

very well set up! Just in case you are not aware, summations can have MANY different answers so... often you will see your way is not the same as the back of the book. Doesn't mean you are wrong though! I remember WAY more often than not, my approach wasn't the same

Answer 11

Do you mind helping me with one more I am confused with?

Answer 12

sure thing

Answer 13

Write the sum using summation notation, assuming the suggested pattern continues.

64 + 81 + 100 + 121 + ... + n2 + ...

Answer 14

see a pattern by any chance?

Answer 15

sorta. It's the difference of the two numbers + 2

Answer 16

oh? can you explain?

Answer 17

81-64 = 17
100-81=19
121-100=21
...

Answer 18

aha! that looks right! now we need an equation that works. i like to pick what i want my lower bound to be first and make an equation that will work with it

Answer 19

the n is adding 2 to itself right?

Answer 20

(n+2) looks like a pretty good candidate to have in your equation.

Answer 21

oooh that also!

Answer 22

awesome! thanks