1.

If a=lambdahati+2hatj-3hatk, b=2hati+lambdahatj-hatk, c=hati+2hatj+hatk and [abc]=6, then lambda is equal to

Answer»

`-8 or 3`
`-9 or 3`
`-3 or +9`
`8 or 5`

Solution :Now, [a b c] `=| (LAMBDA, 2 , -3),(2,lambda,-1),(1,2,1)|`
On applying `C_(1) to C_(1)-C_(3)`, we get
`=|(lambda+3, 2 , -3),(3, lambda, -1),(0,2,1)|`
`(lambda+3)(lambda+2)-3(2+6)=0`
`RARR lambda^(2)+5lambda - 24=0`
`rArr lambda =- 8 or 3 `


Discussion

No Comment Found

Related InterviewSolutions