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Moose352
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Can anyone point me to some online resources on how to integrate polar equations? Thanks.
HallsofIvy said:IF you are concerned with finding area in polar coordinates, then you have to remember that dArea= r dr dθ rather than the simple dxdy of Cartesian coordinates.
HOWEVER, once you have the integral set up, the actual integration is exactly the same: find an anti-derivative and evaluate at the limits of integration.
He did. The Jacobian of the transformation from polar coordinates to Cartesian coordinates is r.Chrono said:I probably missed this, but don't you also have to express the integrand in polar coordinates as well as find the jacobian?
hypermorphism said:He did. The Jacobian of the transformation from polar coordinates to Cartesian coordinates is r.
That is the Jacobian I was referring to, as it implies x and y are functions of r and theta. ;) The derivation in modern terms would be as follows:dextercioby said:It's actually the other way around.What do you make of this
[tex] J = |\frac{\partial (x,y)}{\partial (\rho,\phi)}|=...=r [/tex]
Daniel.
hypermorphism said:He did. The Jacobian of the transformation from polar coordinates to Cartesian coordinates is r.
dextercioby said:I stressed out the fact that the Jacobian i gave (and with which u agreed) (namely "r") is not the jacobian of the transformation from polar ----> cartesian,but from cartesian -------->polar...That's what i meant by "It's actually the other way around"...
Daniel.
hypermorphism said:He did. The Jacobian of the transformation from polar coordinates to Cartesian coordinates is r.
Hi Chrono,Chrono said:Actually, I was suggesting that [tex]r drd\theta[/tex] is the jacobian. And that you need to transform the integrand itself into polar coordinates.
hypermorphism said:Hi Chrono,
This may just be the terminology I've been exposed to, but in the studies I've done, the Jacobian is defined as the determinant of the Jacobian matrix, which is just r. The term [tex]r dr\wedge d\theta[/tex] is the pullback of the volume form of the transformation, which can be simplified to being just the new volume form scaled by the Jacobian. I can see taking the whole thing to be the Jacobian, though, by de-emphasizing the matrix and using only exterior algebra to define the Jacobian.
Polar equations are mathematical equations that describe curves and shapes in two-dimensional polar coordinates, where the position of a point is determined by its distance from the origin and its angle from a fixed reference line. They are important because they can be used to model and understand complex geometric shapes, such as circles, spirals, and cardioids.
To convert a polar equation to rectangular coordinates, you can use the following formulas:x = r * cos(theta)y = r * sin(theta)where r is the distance from the origin and theta is the angle from the reference line. These formulas can be derived from the Pythagorean theorem and trigonometry.
To graph a polar equation, you can follow these steps:1) Plot points by substituting different values for theta into the equation.2) Connect the points to create a smooth curve.3) Identify any symmetries or special features of the graph, such as symmetry about the origin or a vertical line.
Yes, polar equations can be used to model real-world phenomena, such as the motion of planets in orbit, the shape of a hurricane, or the growth of a snail's shell. These equations can also be used in engineering and physics to describe the behavior of physical systems.
One limitation of polar equations is that they can only describe shapes in two dimensions. They also have a limited range of applicability compared to rectangular coordinates, as they cannot accurately represent vertical or horizontal lines. Additionally, some equations may be more difficult to graph in polar coordinates compared to rectangular coordinates.