# Commentary for "Using Snell's Law to determine the fastest escape route"

#### agentmulder

##### Active member
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#### MarkFL

Staff member
Re: Using Snell's Law to determine the fastest escape route

I remember seeing this as Fermat's Principle in an optics book by Pedrotti and Pedrotti but your derivation is much nicer with all the details so someone like me can understand.

Fermat's principle - Wikipedia, the free encyclopedia

Thank you...I find unless I work out the details myself, I don't really understand either.

I think this is testament to the goals of our site, that we allow the students to solve their problems with only suggestions and hints, and get them to come to a better understanding this way.

#### agentmulder

##### Active member
Re: Using Snell's Law to determine the fastest escape route

Thank you...I find unless I work out the details myself, I don't really understand either.

I think this is testament to the goals of our site, that we allow the students to solve their problems with only suggestions and hints, and get them to come to a better understanding this way.
Yep, the goal of a great educator is to help create students that can think on their own. I usually try to do the same unless i get a feeling the student won't be able to get the result on their own. It took the genius of a fermat to properly explain the principle of least time, not all students are geniuses but it's nice when a teacher get's one that is. (Of course i kept that opinion to myself when I was tutoring)

#### Bacterius

##### Well-known member
MHB Math Helper
Re: Using Snell's Law to determine the fastest escape route

It took the genius of a fermat to properly explain the principle of least time
Where can I acquire one of those "fermats"? I could use one

#### agentmulder

##### Active member
Re: Using Snell's Law to determine the fastest escape route

Where can I acquire one of those "fermats"? I could use one
There are probably a few on math forums like this, you can usually tell by quality of postings and the help is free so you don't have to be a marquis to benefit from the knowledge!