- #1

MFAHH

- 32

- 1

## Homework Statement

I've attached the problem

## Homework Equations

d*sinθ=mλ

## The Attempt at a Solution

I've tried a couple of methods. I considered solving for m when θ=90 degrees => sinθ=1 because 90 degrees is the highest possible angle and will (in my mind at least) yield the highest order of spectrum by rounding the resultant value of m down to the nearest integer. But I don't know how to factor the two given wavelengths into all this.

I then considered fiddling about with approximations like, at small angles, tanθ=sinθ=θ=y/L but to no avail.

Can anyone help me on how to solve this? I don't even know how to picture the problem and draw a diagram.