How to get frequency, w (omega), when calculating reactance

[KingDaniel]

Hi,
I came across a question from our weekly set of questions that involved finding the inductive reactance and capacitive reactance, ie: X_L = jwL and X_C = 1 / jwC.
In the solution sheet, the professor wrote that the frequency, w (omega) = 10000, however, in the question sheet, it was nowhere to be found. Is 10000 the standard frequency or is there a way of determining it?
I will upload 2 images of the solution to illustrate my query:

 

[analogdesign]

The frequency is specified as is = 6 cos(10^3t) in the form Acos(wt). So I think it might be a typo. I think omega should be 1000, not 10000.

 

[KingDaniel]

@analogdesign , Oh yeah, of course. My bad. Thanks