Vectors 1 Question 31

32. Suppose that p,q and r are three non-coplanar vectors in R3. Let the components of a vector s along p,q and r be 4,3 and 5 , respectively. If the components of this vector s along (p+q+r), (pq+r) and (pq+r) are x,y and z respectively, then the value of 2x+y+z is

(2015 Adv.)

Show Answer

Answer:

Correct Answer: 32. (9)

Solution:

  1. Here, s=4p+3q+5r

and s=(p+q+r)x+(pq+r)y+(pq+r)z

4p+3q+5r=p(x+yz)+q(xyz)+r(x+y+z)

On comparing both sides, we get

x+yz=4,xyz=3 and x+y+z=5

On solving above equations, we get

x=4,y=92,z=722x+y+z=8+9272=9



NCERT Chapter Video Solution

Dual Pane