Question

Please help me with the question​

Answer 1

Answer:
`\cos^(-1) \left((-22)/(√(754)) \right)`

Explanation:

`a \cdot b=(3)(0)+(-4)(5)+(-1)(2)=-22\\\\|a| |b|=√(3^2 +4^2 +1^2) √(5^2 +2^2)=√(754)\\\\\therefore \cos \theta=\frac{-22}[√(754)}\\\\\theta=\cos^(-1) \left((-22)/(√(754)) \right)`