I know from linear algebra that you can take two things, and if they are equal to each other then you can simply substitute different variables to develop a proof of a different statement.(adsbygoogle = window.adsbygoogle || []).push({});

For example take,

w = a

w = z + k

therefore proof would posit that a = z + k

But my dilemma lies in what my physics book sometimes does. It derives a "proof" by taking two equations and dividing them by each other to attain a different statement.

For example,

w = a

b = k

[tex]\frac{w}{b}=\frac{a}{k}[/tex]

??? This baffles me. What mathematical theorem or algebraic statement lets us derive something by taking two equations and dividing them by each other? There doesn't seem to be any connection or logic between steps.

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Laws of truth and derivation

Loading...

Similar Threads for Laws truth derivation |
---|

I Astrodynamics Question: Derivation of Sp. Orbital Energy? |

A Second derivative of a complex matrix |

I How to find the matrix of the derivative endomorphism? |

**Physics Forums - The Fusion of Science and Community**