Question

Find the projection of the vector `hati + 3hatj + 7hatk`  on the vector `7hati - hatj + 8hatk`.

Answer 1

Let `veca = hati + 3hatj + 7hatk` तथा `vecb = 7hati - hatj + 8hatk`

Example of `veca` on `vecb`

`= (veca xx vecb)/(|vecb|)`

`= ((hati + 3hatj + 7hatk)(7hati - hatj + 8hatk))/(|7hati - hatj + 8hatk|)`

`= (1.7 + 3(-1) + 7.8)/(sqrt(7^2 + (-1)^2 + 8^2))`

`= (7 - 3 + 56)/(sqrt(49 + 1 + 64))`

`= 60/sqrt114`