CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

If a and b are mutually perpendicular unit vectors, then  (3a+2b)(5a6b)=
  1. 5  
  2. 3   
  3. 6    
  4. 12    


Solution

The correct option is B 3   
a and b are perpendicular.
ab=ba=0
Also,|a|=|b|=1
Now, (3a+2b)(5a6b)
=3a(5a6b)+2b(5a6b)
=15|a|218ab+10ba12|b|2
=1512=3

flag
 Suggest corrections
thumbs-up
 
0 Upvotes


Similar questions
View More


People also searched for
View More



footer-image