# Express this current as a single phasor

I have an asignment where I am supposed to express a current:

$$12sin(400t+100^o)$$

as a phasor. I am not shure what that means but I guess that I should express it on the form $$A\angle\theta$$ where $$Acos(\omega t+\theta)$$

How do I do that?

I tried, but looking at the solution, it seems to be that I should divide 12 by $\sqrt{2}$ and I don't know why.

Here is my solution which is wrong:

$$12sin(400t+100^o)=12cos(90^o-400t-100^o)=12cos(-400t-10^o) \Rightarrow 12\angle 10^O$$

I am also curious to know why $\omega$ seems to not affect the answer...