- #1
Jbreezy
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Homework Statement
If you sum this
from one to infinity.
Ʃ (cos(1/(n)^2 - cos(1/(n+1)^2)
Homework Equations
The Attempt at a Solution
Ʃ (cos(1/(n-1)^2 - cos(1/(n+1)^2)
This is telescoping if you work that out for the partial nth partial sum you get
cos(1) - cos(1/(n+1)^2) if you take the limit you get cos(1) -1 which is negative. If you punch it in on wolfram you get the same thing. Can the partial sum be negative ?