Question

Summation question: How do I find the sum of [(i-1)^2 + (i+3)^3] when i= 1 and n= 4?
Thanks in advance for help!

Answer 1

\[\sum_{i=1}^{4} [(i-1)^2 +(i+3)^3]\]

Answer 2

is i real or imaginary?

Answer 3

i is the index of summation

Answer 4

I is the variable that is changing in the summation

Answer 5

so you can do this step by step, start with i= 1, (1-1)^2+(1+3)^2
then you can move to i=2, (2-1)^2+(2+3)^2 and then repeat till i = 4, and add all of them together.

Answer 6

by i =3 you should see a pattern.

Answer 7

ok so i just find the answer for each i, of which there are 4, and add them up?
my brain makes out summations to be harder than they are, i suppose.
but for your second part, the second parentheses is cubed

Answer 8

(i+3)^3