Well, this problem should be solved by Marius' law. This is the main way to deal with polarization. The light intensity passing through P 1 is icos (a) 2, and then passes through p2icos (a) 2cos (90-a) 2.

Where i is that intensity of incident light.

After simplification, (1/4) IO (SIN2A) 2 is obtained.

The landlord may be thinking too much. Physics problems should be well founded. Don't think objectively.

This is Marius' law. No, you can find relevant information.