1.

If a=hat(i)+hat(j)-2hat(k), b=2hat(i)-hat(j)+hat(k) and c=3hat(i)-hat(k) and c=ma+nb, then m+n is equal to

Answer»

0
1
2
`-1`

Solution :Given , ` a =HATI +hatj -2hatk, b =2hati -hatj+HATK, c=3hati and c=m +a+nb`
`THEREFORE 3hati-hatk=m(hati+hatj-2hatk)+n(2hati-hatj+hatk)`
`implies3hati-hatk=(m+2n)hati+(m-n)hatj+(-2m+n)hatk`
On equationg the coefficients of `hati,hatj and hatk,` RESPECTIVELY, we get
`3=m+2n,0=m-n`
`and -1=-2m+n`
`implies3=n+2n`
`impliesn=1`
`impliesm=1and n=1`
` impliesm+n=1+1=2`


Discussion

No Comment Found

Related InterviewSolutions