Answer
Formulas A, B, and E are valid even if the angular acceleration is not constant.
Work Step by Step
Formulas A and B correctly relate rates of change at an instant in time, and thus are valid even if these rates vary over time.
Formula C relates the angular velocity at 2 different times, and is true only when the angular velocity varies linearly.
Formula D is not correct at all – it is the radial acceleration that equals $\omega^2 r$, not the tangential acceleration.
Formula E correctly gives the kinetic energy of an object as a function of its instantaneous angular speed, and so this formula remains true even as the angular speed changes.
