DRV8711 Current Limiting Resistor Watt?

Hello,

I am going to use drv8711 to drive a stepper motor with 48V and 4.2A max.

As i calculated  i need 0.130 Ohm resistor but can not figure out what should limiting resistor watt is?

P=I^2xR = (4.2)^2x0.130=2.3 Watt according to DC.

But i think current is feeded to motor from driver as sine wave and it acts like AC.

Is there any mistake in my calculations?

Thank You