Two light sources of known wavelengths (w1, w2) are displayed through a grating. The screen is a known distance apart, and the spacing between slits is also known. The final given piece of information is the distance between a maxima of the first wavelength and a maxima of the second wavelength. Find the value of m (m being the coefficient/scalar of the wavelength(s) to create constructive interference). I realize that sin(Q) = mw1 / d and that tan(Q) = y1 / L, where y1 is the distance of the maxima from origin. Similarly, sin(D) = mw2 / d and tan(D) = y2/L. However, I can't figure out a way to determine y1 and y2! The distance between distinct maximas is known, but the distance of one maxima to the origin and the second maxima to the origin is hard to find out! Thank you.