Question

What is `|| <-1, -9, -2 > - < -2 , -4, 1 > ||`?

Answer 1

The answer `=sqrt35`

Explanation:

First, we start by subtracting the vectors
`∥〈-1,-9,-2〉-〈-2,-4,1〉∥=∥〈-1+2,-9+4,-2-1〉∥`
`=∥〈1,-5,-3〉∥`
Then we calculate the modulus
`=sqrt(1+25+9)`
`=sqrt35`