The equation you mentioned, C = frequency * wavelength, represents the relationship between the speed of light (C), the frequency of the wave (frequency), and the wavelength of the wave (wavelength). If the frequency is doubled while the wavelength remains the same, the equation would change as follows:
Let's denote the original frequency as f and the new frequency as 2f (double the original frequency). The wavelength remains unchanged, so we can still represent it as λ.
Original equation: C = frequency * wavelength
Substituting the new values: C = (2f) * λ
Simplifying: C = 2 * (f * λ)
In the modified equation, the frequency is doubled, but the wavelength remains the same. Therefore, the product of the frequency and wavelength, represented as (f * λ), remains unchanged. However, the speed of light (C) would still be the same since it is a fundamental constant.