Flag Magical Mathematics[Interesting Approach]> how to proof:- acotA+bcotB+ccotC=2(R+r)...
question mark

how to proof:-
acotA+bcotB+ccotC=2(R+r)

kunalrawat , 11 Years ago
Grade 11
anser 1 Answers
Sunil Raikwar
Hello students, please check the solution given below:

acotA + bcotB + ccotC
= 2RsinAcotA + 2RsinBcotB + 2RsinCcotC
= 2RcosA + 2RcosB +2RcosC
= 2R(cosA+cosB+cosC)
= 2R(1+4sin(A/2)sin(B/2)sin(C/2))
= 2R(1+r/R)
= 2(R+r)
Last Activity: 11 Years ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments