Answer:
The path difference between the two waves should be one-half of a wavelength.
Step-by-step explanation:
For the destructive interference to form at point P the path difference between the two waves should be
=
![(2n+1)(\lambda)/(2)](https://img.qammunity.org/2020/formulas/social-studies/high-school/z5nh6vr43j7rh686ah1wsucu5w0klcqc8r.png)
where n can be any integer starting from 0,1,2....
therefore we can say that
If the maximum destructive interference is to occur at point P, The path difference between the two waves should be one-half of a wavelength.