Determine the dc voltages, assuming K = 1 mA/V2 and VTH = 1V

Formulae for n-channel MOSFET

iDS = K[2(vGS-VTH)vDS - v^2DS] for triode region

iDS = K(vGS-VTH)^2 for saturation region

(I'm not sure why VTH is not given negative for this P-channel MOSFET - any suggestions?)

My solution (not sure!):

Let us consider P-channel MOSFET (as shown in picture) is operating in saturation.

IDS = K(vGS-VTH)^2 [ we have I = Is = Is = IDS = 2mA]

or, 2 = 1 (VGS - 1)^2

or, VGS = 1 plus/minus 2 square-root

or, VGS = 2.141V or -0.414V

As for P channel, VGS has to be less or more negative than that of VTH.

So, VGS = -0.414V

Applying KVL from Source to Get:

10 - VS - VSG = 0

or, VS = 10 + VGS = 9.59V

Now, VD = 6.8*2 - 10 = 3.6 V

VDS = VD - VS = 3.6 - 9.59 = - 5.99V

So, VGS = VG - VS

or, VG = -0.414 - 9.59 = 9.18V

Test, for saturation VDS ≤ VGS - VTH

-5.99 ≤ -0.414 - 1 true!

Please check my calculations and advise, Thanks.

cktMan