Question

If `A= <2 , 6 >` and `B= <-1,9 >`, what is `||A+B|| -||A|| -||B||`?

Answer 1

The answer is `=sqrt226-sqrt82-sqrt40`

Explanation:

`vecA+vecB=〈2,6〉+〈-1,9〉=〈1,15〉`
The modulus of `vecA=∥〈2,6〉∥=sqrt(2^2+6^2)=sqrt40`
The modulus of `vecB=∥〈-1,9〉∥=sqrt(1+81)=sqrt82`
Themodulus of `vecA+vecB=∥〈1,15〉∥=sqrt(1+225)=sqrt226`

`∥vecA+vecB∥-∥vecA∥-∥vecB∥=sqrt226-sqrt82-sqrt40`