trying to get you all confused between thrust and power
Aviator1982,
sorry to have to say it, but in your case the examiner has succeeded.
Thrust required = Drag.
Drag = 1/2 rho V^2 S Cd
Fixed IAS = Fixed 1/2 rho V^2
Therefore thrust is unchanged.
Power = Force x Speed.
Power required = Drag x TAS
Less density, same IAS means increased TAS.
Therefore power required is increased
(And that not even taking into account reduced power for a given RPM by density reduction.)
C FTW!
pb
pb