Guest

cos 2 A+cos 2 B+cos 2 C=cosB×cosC+cosC×cosA+cosA×cosB then prove that the trangle are equilateral

cos2A+cos2B+cos2C=cosB×cosC+cosC×cosA+cosA×cosB then prove that the trangle are equilateral

Grade:12th pass

1 Answers

Aditya Gupta
2081 Points
5 years ago
let cosA=x, cosB=y, cosC=z
the given equation becomes 
(x-y)^2+(y-z)^2+(z-x)^2=0
so cosA=cosB=cosC implying that A=B=C, therefore the triangle is equilateral

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free