I would need to simplify or approximate this expression:
Abs[0.00178442 Cos[alpha] - 0.0368414 Sin[alpha] + (0.998216 Cos[alpha] + 0.0368414 Sin[alpha]) (Cos[2 dx] + I Sin[2dx])]^4
I have tried with the Expand and Simplify/FullSimplify commands in Mathematica but it does not calculate the Abs[]^4. Could anyone help with me with this issue?