Toronto Math Forum
APM3462012 => APM346 Math => Misc Math => Topic started by: Kun Guo on November 10, 2012, 05:33:03 PM

Attached picture is a screen shot of online notes lecture 23. I was wondering if there is an addition r in front of sin(n*theta) in (12). Also, is there missing a^(n) in calculating An and Cn?

Good catch

I don't understand, if in equation (12) we are plugging in r=a to eq(10) how is there still and r involved as a variable?

I don't understand, if in equation (12) we are plugging in r=a to eq(10) how is there still and r involved as a variable?
We plug $r=a$ to recover coefficients (which do not depend on $r$). After they are recovered we plug them to the original expression for $u$ which still contains $r$.

I was wondering if Cn has to be sin(nÎ¸) instead of cos(nÎ¸)?

I was wondering if Cn has to be sin(nÎ¸) instead of cos(nÎ¸)?
Yes, corrected.