- #1
thegreenlaser
- 525
- 16
My issue comes from thermodynamics (https://www.physicsforums.com/threads/zeroth-law-of-thermodynamics-and-empirical-temperature.774255/), but I guess this is really a math problem rather than a physics problem:
Let [itex] \boldsymbol{x} \in \mathbb{R}^m [/itex], [itex] \boldsymbol{y} \in \mathbb{R}^n [/itex], [itex] \boldsymbol{z} \in \mathbb{R}^p [/itex].
Given
[tex] f_1 (\boldsymbol{x}, \boldsymbol{z} ) = f_2 (\boldsymbol{y}, \boldsymbol{z}) [/tex]
and
[tex] f_3(\boldsymbol{x}, \boldsymbol{y}) = 0, [/tex]
how can we show that there exist functions [itex] g_1, g_2 [/itex] such that
[tex] g_1(\boldsymbol{x}) = g_2(\boldsymbol{y}) [/tex]
(i.e., [itex] f_3 = 0 [/itex] means that [itex] f_1 [/itex] and [itex] f_2 [/itex] can be reduced so they're independent of [itex] \boldsymbol{z} [/itex])
In my physics class, we were given a sort of "hand-waving" argument, but I'm having trouble finding a more rigorous explanation. Can anyone help me out?
Let [itex] \boldsymbol{x} \in \mathbb{R}^m [/itex], [itex] \boldsymbol{y} \in \mathbb{R}^n [/itex], [itex] \boldsymbol{z} \in \mathbb{R}^p [/itex].
Given
[tex] f_1 (\boldsymbol{x}, \boldsymbol{z} ) = f_2 (\boldsymbol{y}, \boldsymbol{z}) [/tex]
and
[tex] f_3(\boldsymbol{x}, \boldsymbol{y}) = 0, [/tex]
how can we show that there exist functions [itex] g_1, g_2 [/itex] such that
[tex] g_1(\boldsymbol{x}) = g_2(\boldsymbol{y}) [/tex]
(i.e., [itex] f_3 = 0 [/itex] means that [itex] f_1 [/itex] and [itex] f_2 [/itex] can be reduced so they're independent of [itex] \boldsymbol{z} [/itex])
In my physics class, we were given a sort of "hand-waving" argument, but I'm having trouble finding a more rigorous explanation. Can anyone help me out?