If `veca=hati+hatj + hatk and vecb = hati - 2 hatj+hatk` then find the vector `vecc` such that `veca.vecc =2 and veca xx vecc=vecb`.

Explanation

`vecaxx vecb = vecaxx(vecaxxvecc) = (veca.vecc)veca- (veca.veca)vecc`
`2veca - 3vecc`
But `veca xx vecb = 1|{:(hati,hatj , hatk),(1,1,1),(1,-2, 1):}|= 3hati-3hatk`
Hence, `3vecc= 2veca - (3hati - 3hatk)`
`= (2hati + 2hatj =2hatk)-(3hati - 3hatk)`
`= - hati + 2hatj + 5hatk`
`or vecc = 1/3 (-hati = 2hatj + 5hatk) `