Find (∂a/∂θ) given 3 equations

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SUMMARY

The discussion centers on finding the partial derivative (∂a/∂θ) given the equations for converting spherical coordinates to Cartesian coordinates: x = r*sin(a)*cos(θ), y = r*sin(a)*sin(θ), and z = r*cos(a). The user initially confused the variables and attempted to apply the chain rule without success. It was clarified that ∂ϕ/∂θ = 0, indicating that φ and θ are independent variables in spherical coordinates, which simplifies the problem. The correct approach involves differentiating with respect to the appropriate variable.

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Homework Statement


Find (∂a/∂x) if
x = r*sin(a)*cos(θ),
y = r*sin(a)*sin(θ),
z =r*cos(a).
The equations originally have phi in place of a, but I switched it to a for ease of typing.

Homework Equations


Chain rule?

The Attempt at a Solution


I'm not exactly sure where to start. I tried using the chain rule and differentiating with respect to x but then I just end up with too many unknown and nothing really simplifies. How exactly does one go about solving this problem? Thanks ahead of time for any help.
 
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MeMoses said:

Homework Statement


Find (∂a/∂θ) if
x = r*sin(a)*cos(θ),
y = r*sin(a)*sin(θ),
z =r*cos(a).
The equations originally have phi in place of a, but I switched it to a for ease of typing.


Homework Equations


Chain rule?


The Attempt at a Solution


I'm not exactly sure where to start. I tried using the chain rule and differentiating with respect to x but then I just end up with too many unknown and nothing really simplifies. How exactly does one go about solving this problem? Thanks ahead of time for any help.
Unless I'm missing something here, ∂[itex]\phi[/itex]/∂θ = 0, which is the case whenever you have partials involving two independent variables.
The equations you gave above are just the equations to convert from spherical coordinates to rectangular (or Cartesian) coordinates (but r should be replaced by ρ). In spherical coordinates, [itex]\phi[/itex] and θ have no connection, so neither is a function of the other, making them independent variables.
 
crap I meant Find (∂ϕ/∂x) which should make more sense and explains why I tried differentiating with respect to x. Now that that's clear where exactly do I start?
 

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