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View Full Version : Cos(x)+sin(x) = 0, Find all values?


DrummingAtom
Oct6-10, 11:35 AM
1. The problem statement, all variables and given/known data
Cos(x)+sin(x) = 0, Find all values?



2. Relevant equations



3. The attempt at a solution
I've found the first solution, which is 3pi/4 and I figured I can just add pi to that value over and over to obtain the infinite other values. But when I punch it in my calculator it's coming up that cos(7pi/4)+sin(7pi/4) = 0.000000000021

I'm not sure if this is a calculator computation issue or I'm doing something wrong.. Thanks for any help.

Mark44
Oct6-10, 11:59 AM
1. The problem statement, all variables and given/known data
Cos(x)+sin(x) = 0, Find all values?



2. Relevant equations



3. The attempt at a solution
I've found the first solution, which is 3pi/4 and I figured I can just add pi to that value over and over to obtain the infinite other values. But when I punch it in my calculator it's coming up that cos(7pi/4)+sin(7pi/4) = 0.000000000021

I'm not sure if this is a calculator computation issue or I'm doing something wrong.. Thanks for any help.
No, you're not doing anything wrong. This error is due to the calculator.