Question

The force F =(i+bſ + 3)N is rotated through an
angle a , then it becomes (2i +(2b - 1)j + k N
The value of b is :-
2
(1) 2
(2) - 3
2
(3)
(4) Both (1) and (2)
why on rotating magnitude of vector will remain same???
this is the real question....​

Answer 1

Answer:

plz hindi me bolo na muze samaz nahi aaya hai

Answer 2

see the attachments

hope it helps..