- #1
Grufey
- 30
- 0
Hi everyone!
I'm not sure if this is the right forum to post my question. If I'm wrong, let me know it.
The question:
Let us consider the functions [itex]\theta=\theta(x,y)[/itex], and [itex]M=M(\theta)[/itex], where M is a operator, but i doesn't relevant to the problem. I need to know the derivative [tex]\frac{\partial M}{\partial \theta}[/tex] in terms of x and y. Additional information: x and y are the longitud and latitude of a sphere, thus, every arc of sphere, θ, can be descomposed in two arcs, one associated to longitud and other associated with the lattitude. This is the aim of achieve the ∂M/∂θ in terms of x and y.
It's a trivial question, but I'm stuck...
This is my try...
[tex] dM=\frac{\partial M}{\partial x}dx+\frac{\partial M}{\partial y}=\frac{\partial M}{\partial \theta}d\theta=\frac{\partial M}{\partial \theta}\frac{\partial \theta}{\partial x}dx+\frac{\partial M}{\partial \theta}\frac{\partial \theta}{\partial y}dy[/tex]
Therefore, I get, [tex]\frac{\partial M}{\partial x}=\frac{\partial M}{\partial \theta}\frac{\partial \theta}{\partial x}[/tex] and[tex]\frac{\partial M}{\partial y}=\frac{\partial M}{\partial \theta}\frac{\partial \theta}{\partial y}[/tex]
But, if this calculus are right, them ∂M/∂θ has two differents expressions, due to I get two equations. I'm stuck
Thanks in advance
Regards
I'm not sure if this is the right forum to post my question. If I'm wrong, let me know it.
The question:
Let us consider the functions [itex]\theta=\theta(x,y)[/itex], and [itex]M=M(\theta)[/itex], where M is a operator, but i doesn't relevant to the problem. I need to know the derivative [tex]\frac{\partial M}{\partial \theta}[/tex] in terms of x and y. Additional information: x and y are the longitud and latitude of a sphere, thus, every arc of sphere, θ, can be descomposed in two arcs, one associated to longitud and other associated with the lattitude. This is the aim of achieve the ∂M/∂θ in terms of x and y.
It's a trivial question, but I'm stuck...
This is my try...
[tex] dM=\frac{\partial M}{\partial x}dx+\frac{\partial M}{\partial y}=\frac{\partial M}{\partial \theta}d\theta=\frac{\partial M}{\partial \theta}\frac{\partial \theta}{\partial x}dx+\frac{\partial M}{\partial \theta}\frac{\partial \theta}{\partial y}dy[/tex]
Therefore, I get, [tex]\frac{\partial M}{\partial x}=\frac{\partial M}{\partial \theta}\frac{\partial \theta}{\partial x}[/tex] and[tex]\frac{\partial M}{\partial y}=\frac{\partial M}{\partial \theta}\frac{\partial \theta}{\partial y}[/tex]
But, if this calculus are right, them ∂M/∂θ has two differents expressions, due to I get two equations. I'm stuck
Thanks in advance
Regards
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