Get Answers to all your Questions

header-bg qa

Let a,b and c be non zero vectors such that (a cross b)cross c=1/3 |b||c| a. if theta is an angle between the vectors b and c, then sin theta equals

Answers (1)

best_answer

 Solution:

ecause (a	imes b)	imes c=1/3left | b 
ight |left | c 
ight |aRightarrow (acdot c)b-(bcdot c)a=1/3left | b 
ight |left | c 
ight |a\ \Rightarrow (acdot c)b=[(bcdot c)+1/3left | b 
ight |]left | c 
ight |a\ \Rightarrow (acdot c)b=left | b 
ight |left | c 
ight |[cos	heta +1]a

As a and b are not parallel acdot c=0;and;cos	heta +1/3=0

\Rightarrow cos	heta =-1/3Rightarrow sin	heta =2sqrt2/3

Posted by

Deependra Verma

View full answer