Hello,(adsbygoogle = window.adsbygoogle || []).push({});

I am working my way through Cal vo1 by Apostol and working the problems and was wondering if someone could assist.

The question is on pg 19 to prove theorems i.5-i.15 using axioms and theorems i.1-i.4.

Theorem i.5 states a(b-c) = ab - bc.

I started the proof but am stuck at at the point indicated below.

a(b-c) = a(b + (-c)) = ab + a(-c)

being able to represent a(-c) as -ac is not illustrated until theorem i.12.

I tried representing a(-c) as -(-a)(-c) but that did not go anywhere either due to (-a)(-c) not being illustrated until i.12 either.

Can anyone help me along with this one. This is not a hw assignment as I am a BS in EE with a minor in math. Just working my way through this book to enhance my knowledge.

Thanks,

Chad

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

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

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

# Cal proof (Apostol)

Loading...

Similar Threads for proof Apostol |
---|

B Proof of a limit rule |

B Proof of quotient rule using Leibniz differentials |

B Don't follow one small step in proof |

**Physics Forums | Science Articles, Homework Help, Discussion**