Step 1: Formation of stationary waves.
A stationary wave is formed by the superposition of two identical progressive waves having the same amplitude, frequency, and wavelength but traveling in opposite directions.
Step 2: Wavelength relation.
The wavelength of the stationary wave is equal to the wavelength of the individual progressive waves.
Step 3: Interpretation of nodes and antinodes.
In a stationary wave, the distance between two consecutive nodes or antinodes is \( \frac{\lambda}{2} \), but the full wavelength remains \( \lambda \).
Step 4: Final conclusion.
Hence, the wavelength of the stationary wave is \( \lambda \).