Sure, the 6th harmonic of a wave can be found by multiplying the fundamental frequency by the harmonic number.
Given the fundamental frequency is 15Hz, and we're trying to find the 6th harmonic, we can proceed with the calculation.
Step 1: Identify the fundamental frequency. In this case, it is 15Hz.
Step 2: Identify the harmonic number, which is the number of times the fundamental frequency is contained in the harmonic. Here, it is 6.
Step 3: Multiply the fundamental frequency by the number of the harmonic. So, we calculate 15Hz (fundamental frequency) * 6 (harmonic number).
As a result, the 6th harmonic of the wave is 90Hz.