Answer:

Step-by-step explanation:
From the question we are told that:
Frequency of 3rd harmonics

Frequency of 5th harmonics

Generally the equation for Wavelength at 3rd Harmonics is mathematically given by

Therefore

Generally the equation for Wavelength at 1st Harmonics is mathematically given by

Therefore

Generally the equation for the frequency of the first harmonic is mathematically given by


