No, your statement is not accurate. In AM (Amplitude Modulation) and FM (Frequency Modulation) radio broadcasting, the modulation schemes are different, but they do not imply constant properties as you described.
In AM radio broadcasting, the amplitude of the carrier wave is modulated to carry the audio signal. The audio signal varies the amplitude of the carrier wave, allowing the transmission of sound. The frequency of the carrier wave remains constant throughout the transmission.
In FM radio broadcasting, the frequency of the carrier wave is modulated to carry the audio signal. The audio signal varies the frequency of the carrier wave, resulting in variations in the pitch or frequency of the transmitted signal. The amplitude of the carrier wave can still vary, but it is not the primary means of carrying the audio information.
Therefore, in AM radio, the amplitude of the carrier wave varies, while the frequency remains constant. In FM radio, the frequency of the carrier wave varies, while the amplitude can also vary but is not primarily used for transmitting the audio information.