Answer:
1264 Hz
Explanation:
We are given;
Your distance to the front of first speaker: L1 = 2.79 m
Distance between speakers; d = 1.26m
Now, your distance to second speaker can be calculated using pythagoras theorem.
Thus;
L2 = √(1.26² + 2.79²)
L2 = 3.0613 m
Let's find the wavelength from the formula;
(L1 - L2) = nλ
Where n is the order and could be; n = 0,1,2,3...
Making λ which is the wavelength the subject, we have;
(L1 - L2)/n = λ
The least frequency will occur at the wavelength when n = 1.
λ = (2.79 - 3.0613)/1
λ = -0.2713 m
We will take the absolute value and thus;
λ = 0.2713 m
Frequency is gotten from;
f = v/λ
Where v is speed of sound = 343 m/s
Thus;
f = 343/0.2713
f ≈ 1264 Hz