Phase of a transfer function

[hoki222]

Hi can somebody explain, how to derive the phase function from the following transfer function:

H(s)=s/(s^2+s+1)

I found the Magnitude already to be

|H(jw|=w/root[w^2+(1-w^2)^2]

I know the relationship Angle=arctan(Im/Re) but still cant find the right phase function. Plz Help!

 

[eem2am]

you put in s = jw

then work it thru