+91-93193 64476
FlagBACK
Flag Vectors> if a+b+c=0 and a^2+b^2+c^2=k(a^2-bc) then...
question mark

if a+b+c=0 and a^2+b^2+c^2=k(a^2-bc) then value of k is

Priya , 7 Years ago
Grade 12
anser 1 Answers
divyam gupta
(a+b+c)^2=a^2+b^2+c^2+2ab+2bc+2ca=0
a^2+b^2+c^2=2(-a(b+c)-bc)
from given condition:
a+b+c=0
therfore:b+c=-a
use above condition to get
a^2+b^2+c^2=2(a^2-bc)
therfore,k=2
Last Activity: 7 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


Other Related Questions on vectors

question mark
A body is rotating with an angular velocity of 2radians per second about the line joining (1, 2,3) and (2, 3,5) find the velocity of the particle of the body which is momentarily at (3, 5,6) 
 
vectors
1 Answer Available

Last Activity: 3 Years ago

question mark
Show that: vectorPQ+vectorPR+ vectorPS +vectorTP+vectorUP = 4PQ
Vector
vectors
1 Answer Available

Last Activity: 4 Years ago

question mark
Given that A×(B×C) = (A.C)B - ( A.B)C , deduce that (A×B)×C = (A.C)B - (B.C)A
vectors
1 Answer Available

Last Activity: 4 Years ago

question mark
the mean of 30 observations was 17 with sd2. later it was found that two of the observations were incorrect, which were recorded as 19vand 21.find the correct sd if the incorrect values are deleted and correct values 22 and 15 are included
vectors
1 Answer Available

Last Activity: 4 Years ago

question mark
Find the component of 2i +3j +k in the direction of 3i-j 
 
vectors
1 Answer Available

Last Activity: 4 Years ago