Flag Algebra> trigo...
question mark

if cos3A+cos3B+cos3C=1 then which type of triangle is it? A)obtuse B)acute c)right angled triangle D)none of these

Vatsal Koradia , 15 Years ago
Grade 11
anser 2 Answers
SAGAR SINGH - IIT DELHI

Dear student,

COS3B+COS3C+COS3A=1
COS3B+COS3C+COS3A-1=0
COS3(B+C)/2.COS3(B-C)/2-SIN^3A/2=0
SOLVING WE GET
COS3C/2.COS3B/2.COS3A/2=0
EITHER3C/2=
C=/3     THEREFORE TRIANGLE IS ACUTE ANGLED

Last Activity: 15 Years ago
Harditya
The last part is wrong! 3c/2=pi
c=2pi/3
therefore triangle is obtuse
 
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