Question

find the magnitude of a, the magnitude of b and the scalar product of vectors a and b.

Answer 1

The magnitude of a is

$\lvert a\rvert=\sqrt[]{-5^2+1^2-9^2}=\sqrt[]{25+1+81}=\sqrt[]{107}$

The magnitude of b is

$\lvert b\rvert=\sqrt[]{-1^2-9^2-1^2}=\sqrt[]{1+81+1}=\sqrt[]{83}$

The scalar product of a. b is

$a.b=(-5i+j-9k).(-i-9j-k)$