You need to rotate the polarization direction of some linearly polarized light by an angle φ. That is, the light is initially linearly polarized along some direction (let's call it the y direction), and you need to change it so that the polarization direction is φ away from the y direction. In order to do this, you have two polarizers available. Prove that in order to get the maximum final intensity, you should choose to orient first polarizer at an angle φ=θ/2 from the initial polarization direction. (Note that to achieve the desired final polarization, you have no choice about how to orient the second polarizer.) Anyone care to take a stab at this? im unsure of how to go about proving this. Any help to point me in the right direction would be appriciated, thanks.