I need to work out the angle $\theta$ between these two complex vectors:
$$u=(1+i,2-i)$$ $$v=(2-3i,4+i)$$
I understand I must utilize the following formula:
$$||u|| ||v|| cos(\theta)=\Re(<u,v>)$$
I am unsure how to calculate the modulus $||u||$ of a complex vector though.
Is it:
$$\sqrt{||u_1||^2 + ||u_2||^2} = \sqrt{7}$$
Or something else?