My problem: "Imagine you have two identical perfect linear polarisers and a source of natural light. Place them one behind the other and position their transmission axes at 0° and 90° respectively. If 1000 W.m-2 of randomly polarised light is incident. Determine an expression for the maximum possible intensity of light that can be transmitted through if you insert ‘n’ polarisers between them." I understand that I need to be using, Malus's law which is... [tex] I_θ = I_0 Cos(θ_n)^2[/tex] My attempt: I know that the first and last polariser transmission axes must be at 0° and 90°, I know how to write the expression out... eg. [tex] I_θ = I_0 Cos(θ_1)^2 Cos(θ_2)^2......... Cos(θ_∞)^2[/tex] But I am just not sure how to generalize the expression.