Actually you can find out now. Locate the central spear (what Lucy mentioned). It's the last frond to emerge from the crown. GENTLY, and I do mean gently, tug on it. If it pulls right out of the crown, it's dead. If it doesn't, it's alive.
If your palms pass the tug test, trim off all the dead fronds and wait. Don't fertilize. Palms grow slowly..if it has no fronds, food is not a good thing.
You may have to wait awhile before it grows back out
