hii guys! I'm having trouble with a homework and I was wondering if you could explain something to me. Here's the problem: Two radio antennas A and B radiate in phase. Antenna B is a distance of X meters to the right of antenna A. Consider point Q along the extension of the line connecting the antennas, a horizontal distance of Y meters to the right of antenna B. The frequency, and hence the wavelength, of the emitted waves can be varied. What is the longest wavelength for which there will be destructive interference at point Q? I know I want to use the formula: (r2 - r1) = (m + 1/2)lamda my r2 is the distance from B to Q which is Y meters my r1 is the distance from A to Q which is Y + X meters I'm trying to solve for lamda, but I dont know what m is. I know m has to do with "the longest wavelength" but I'm not sure how to calculate it. Or is it 0? I was guessing it would be 0 or 1. The book isn't clear. I hope you can help me!