If my actions precipitate an accident, do I cause the accident or prevent it?

The answer is “Cause”.

Precipitate is defined as “cause to happen suddenly”

So in this case, if your actions precipitated the accident, then your actions caused the accident to happen.

For example, if your actions were to swerve your car out of the way of a mattress on the road, but you accidentally slammed into a parked car, then your actions to swerve away from the mattress on the road precipitated or caused the accident.

The purpose of a persuasive essay is to convince the audience that writer’s assertion is indeed valid or true.