Find the maximum power
The quoted task seems to be about P(t), power as a function of time or instantaneous power. The instantaneous voltage, real current, reactive current, total current, and power are shown below. Power has been divided by 100 to make a more readable graph. The "positive maximum power" of the task is the positive peak of the power waveform. I determined that graphically as 2938 watts. I will leave it  to the student to determine it analytically.