Let ABC be a triangle with integral side lengths such that angle A=3 * angle B. Find the minimum value of its perimeter.
(In reply to
re(2): NO DICE.....not a spoiler by Ady TZIDON)
I've never seen this formula: a+b+c= 2r*(sina+sin3a+sin4a)
but I looked it up.
r depends on a (as well as b and c) So you can't just take the derivative of (sina+sin3a+sin4a)
Your error was assuming f was the only function that matters.

Posted by Jer
on 20150304 12:28:11 