+91-87964 74404
FlagBACK
Question icon
Grade 10Vectors

Formula of (A vector + B vector).(A vector-B vector)

Profile image of Ramana
6 Years agoGrade 10
Answers icon

3 Answers

Profile image of Arun
6 Years ago
Dear student
 
This is simply dot product.
 
it can be expanded as
 
A.A -A.B + B.A – B.B = B.A – A.B
 
Hope it helps
 
Regards
Arun
Profile image of Saurabh Koranglekar
6 Years ago
576-831_15661761950021451319127.jpg
Profile image of Satwik Banchhor
6 Years ago
Hey Ramana,
This problem can be solved using the following properties of dot product of vectors :-
  1. Distributive Property : A.(B+C) = A.B + A.C
  2. Commutative Property: A.B = B.A
  3. A.A = |A|2 
(A + B) . (A – B) 
= A . (A – B) + B . (A – B)    Using Distributive Property
= A.A – A.B + B.A – B.B      Using Distributive Property
= A.A  – B.B                         As A.B = B.A by Commutative Property
= |A|2 – |B|2
  

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: 4 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