cos2A+cos2B+cos2C=cosB×cosC+cosC×cosA+cosA×cosB then prove that the trangle are equilateral
manoj kumar , 6 Years ago
Grade 12th pass
Trigonometry> cos 2 A+cos 2 B+cos 2 C=cosB×cosC+cosC×co...
1 Answers
Aditya Gupta
Last Activity: 6 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
Provide a better Answer & Earn Cool Goodies
Enter text here...
LIVE ONLINE CLASSES
Prepraring for the competition made easy just by live online class.
Full Live Access
Study Material
Live Doubts Solving
Daily Class Assignments
Ask a Doubt
Get your questions answered by the expert for free
Enter text here...
Other Related Questions on Trigonometry
In ABC, if cot A+cot B+cot C = cosecA cosecB cosecC, then prove that ABC is right angle triangle.
Trigonometry
1 Answer Available
Last Activity: 2 Year ago(s)
\tFind the general solution of equation tan3∂=cot2∂For all angles between -720 and +720
Trigonometry
0 Answer Available
Last Activity: 2 Year ago(s)
To prove : Cosec(45 degree - A)Cosec(45 degree + A) = 2SecA
Trigonometry
0 Answer Available
Last Activity: 2 Year ago(s)
cos^2 13ºcos^2 47º+cos^2 73º =? …..................
Trigonometry
0 Answer Available
Last Activity: 2 Year ago(s)
Derive a formula for the area of the triangle, given b, A, B, and C. That is, derive the formula: (b^2sinAsinC)/(2sinB)
Trigonometry
0 Answer Available
Last Activity: 2 Year ago(s)