THANK YOU! You are the only explanation I've seen that mentions that the rays aren't actually going to be parallel. I understand this makes the equation wrong if you're nitpicky, but the larger the ratio of the distance to the displaying surface to the distance between grating gaps is, the closer it will be to the right answer. In most cases, the ratio is large enough that the difference is so negligible that for all intents and purposes it's not worth considering. I'd see explanations using parallel lines and some with converging lines, but nobody explained the relationship between the two. To me it didn't make sense. Explanations with parallel lines couldn't explain why interference was occurring, because if the lines were truly parallel the light lines would never meet in the same space, so they can't affect eachother. However, in explanations using converging lines, creating a right-angle triangle to split the difference between the lengths of the light paths from different slits to a single point didn't make sense, because the only way to make converging lines equal was to make an isoceles triangle instead, and then none of the trigonometry works.

6 year old video, but this saved me. thank u pete g

Thanks dude, i finally understand diffraction greating now

Thanks, simple & general👍

Thank you so much for doing this :)

what about the minimum equation? can you please explain the order?