- #1
tnutty
- 326
- 1
Homework Statement
can you explain this conversion, I am not sure.
Rectangle coord :
[tex]\int^{2}_{-2}[/tex][tex]\int^{sqrt(4-x^2)}_{-sqrt(4-x^2)}[/tex][tex]\int^{2}_{sqrt(x^2 + y^2 )}[/tex] F(x) dzdydx
=
cylindrical coord :
[tex]\int^{2\pi}_{0}[/tex][tex]\int^{2}_{0}[/tex][tex]\int^{2i}_{r}[/tex] r*dzdrd[tex]\theta[/tex]
I see that x^2 + y^2 = r so the right most integral in cylindrical coordinate is from 2 to r
The middle integral from symmetry runs from 0 to sqrt(4 - x^2), but they have that as 0 to 2
So I am assumming this is what they did :
y = sqrt(4-x^2)
y^2 = 4 - x^2
y^2 + x^2 = 4
r = 2
thus, 0<= r <= 2 ?
and the 0 to 2Pi is just the while circle that's begin read.
Also in the rectangle coordinate, what happened to -2 and 2 in the leftmost integral?