1.

The value of hat(i)xx(hat(i)xxa)+hat(j)xx(hat(j)xxa)+hat(k)xx(hat(k)xxa)is

Answer»

a
`axxhat(k)`
`-2a`
`-a`

Solution :(C) Suppose, `a=a_(1)HAT(i)+a_(2)hat(j)+a_(3)hat(k)`
Now, `(hat(i)XXA)=a_(2)hat(k)-a_(3)hat(j)`
Now`hat(i)XX(hat(i)xxa)=-a_(2)hat(j)-a_(3)hat(k)`
SIMILARLY, `hat(i)xx(hat(j)xxhat(a))=-a_(1)hat(i)-a_(3)hat(k)`
and `hat(k)xx(hat(j)xxa)=-a_(1)hat(i)-a_(2)hat(j)`
`:.hat(i)(hat(i)xxa)+hat(j)(hat(j)xxa)+hat(k)(hat(k)xxa)=-2a`


Discussion

No Comment Found

Related InterviewSolutions