A or an? An or a? It depends. On what? On the word that follows. When deciding which indefinite article you need, sound it out. Use a before a consonant sound and an before a vowel sound. Seems simple and straightforward. It’s not, if the examples I’ve shared here, here and here are any indication.
Independent begins with a vowel sound. So, applying what we’ve learned, we can conclude that an is the answer. Independent is dependent on it. Constantly. No independent variables here.