Implicit Function Theorem (IFT)
en.wikipedia.org
en.wikipedia.org
https://www.reddit.com/r/learnmath/comments/av8w5v/help_me_u...
>"Basically we can see every function in R^n as the level surface of some higher dimensional function in R^n+1"
[...]
>"A level surface is just some constant value of any function."
Also related:
https://en.wikipedia.org/wiki/Jacobian_matrix_and_determinan...