Answer to Question #210178 in Mechanics | Relativity for Vector vee

Question

a=I+2j-3k

b=4i+j-7k.

Find the modulus and direction cosine of the following

b+a

b-a

Answer 1

1)

$$\bold{b+a}=(5,3,-10)\\b+a=\sqrt{134}\\ (\cos a,\cos b,\cos c)=\frac{1}{\sqrt{134}}(5,3,-10)$$

2)

$$\bold{b-a}=(3,-1,-4)\\b-a=\sqrt{26}\\ (\cos a,\cos b,\cos c)=\frac{1}{\sqrt{26}}(3,-1,-4)$$