Question

<p>Prove that for a diffraction grating with N narrow slits the intensity at<br />any principal maximum is I = N2N0, where I0 is the intensity due to one<br />slit. Hint: take <img src="https://s3.amazonaws.com/answer-board-image/cramster-equation-20101021170216342327722196024192219.gif" alt="" align="absMiddle" />, and let <img src="https://s3.amazonaws.com/answer-board-image/cramster-equation-20101021170596342327725948352638888.gif" alt="" align="absMiddle" />.</p>