Homework Statement
Show that: \sum_{n=1}^{\infty}\frac{1}{n^4} = \frac{π^4}{90}
Hint: Use Parseval's theorem
Homework Equations
Parseval's theorem:
\frac{1}{\pi}\int_{-\pi}^{\pi} |f(x)|^2dx = \frac{a_0^2}{2}+\sum_{n=1}^{\infty}(a_n^2+b_n^2)
The Attempt at a Solution
I've been trying to solve...
Homework Statement
Find the centroid x,y,z of the region R cut out of the region 0<=z<=5sqrt(x2+y2) by the cylinder x2+y2=2x.
Homework Equations
x2+y2 = r2
x= rcosθ
y= rsinθ
The Attempt at a Solution
Centroid x being Mx/m I'm guessing
I've been working on this problem...
Homework Statement
At time t, a comet has the position R = (t2-1)i + 2tj
At t = 2, find the radial and circumferential components of velocity and acceleration
Homework Equations
Vr = V * Ur
Vθ = V * Uθ
ar = a * Ur
aθ = a * Uθ
Ur = cosθ i + sinθ j
Uθ = -sinθ i + cosθ j...
Homework Statement
Find
a) the potential difference between points a and b
b) the current of the 20 ohm resistor
I drew the diagram in MS Paint. Should be good enough.
http://img188.imageshack.us/img188/6515/circuitf.jpg [Broken]
2. The attempt at a solution
I just don't know where to...