SOLUTION: Could I please get someone to varify my answer? SUM8(-0.5i+2) i=1 After coming up with the equation 8/2(2+(-2)), I got (0) as my answer. Is this correct? Sorry about the equa

Algebra ->  Sequences-and-series -> SOLUTION: Could I please get someone to varify my answer? SUM8(-0.5i+2) i=1 After coming up with the equation 8/2(2+(-2)), I got (0) as my answer. Is this correct? Sorry about the equa      Log On


   

Question 151887: Could I please get someone to varify my answer?
SUM8(-0.5i+2)
i=1
After coming up with the equation 8/2(2+(-2)), I got (0) as my answer. Is this correct? Sorry about the equation, I was not sure how to type it all and I hope you can figure it out.
Answer by nabla(475) About Me  (Show Source):
You can put this solution on YOUR website!
-.5sum%28+i%2C+1%2C+8+%29%2B2%29
Is this the correct problem?
The solution will not be 0, however.
I will iterate first:
-.5+2-1+2-1.5+2-2+2-2.5+2-3+2-3.5+2-4+2=-2.
Now, formula-wise, remove the constant 2 by properties of summation notation to make it +8*2=+16.
Further, the sum from 1 to n of i is given by n(n+1)/2.
So if n=8,
8(9)/2=36. Now, that is modified by -.5. So -18 is our remaining summation.
-18+16=-2.