Two radio antennas A and B radiate in phase. Antenna B is a distance of 130 m to the right of antenna A. Consider point Q along the extension of the line connecting the antennas, a horizontal distance of 50.0 m to the right of antenna B. The frequency, and hence the wavelength, of the emitted waves can be varied. What is the longest wave lenght that cause constructive interference and what is the longest wavelenght that cause destructive interference r1-r2=(.5+m)[itex]\lambda[/itex] r1-r2=(m)[itex]\lambda[/itex] After a drew my picture I got r1 =180 and r2=50 then I plugged into the formulas 130=.5[itex]\lambda[/itex] destructive=260 130=[itex]\lambda[/itex] constructive Is that right because the problem seems to easy?