Final answer:
To find the reference angle of (frac{7pi}{6} - pi), rewrite pi with a denominator (frac{6pi}{6}) and subtract the numerators to get (frac{pi}{6}). There's no need for an LCD in this process.
Step-by-step explanation:
When finding reference angles, the process of subtraction for angles in radians does not require finding a least common denominator (LCD) as you might with fractions. If you have the expression (frac{7pi}{6} - pi), you can treat 'pi' as having a denominator of 1, which allows you to write it as (frac{pi}{1}). For the subtraction, you directly compare the numerators while the denominators remain as they are. So, (frac{7pi}{6} - frac{pi}{1}) is the same as (frac{7pi}{6} - frac{6pi}{6}), which simplifies to (frac{7pi - 6pi}{6}) or (frac{pi}{6}). This is the reference angle you're looking for, and there's no need to complicate the process with an LCD.
Using a calculator sometimes does the simplification automatically, and it is important to understand how to simplify expressions by hand as well. This ensures you not only get the correct answer but also understand the steps required to get there. Remember to check your answer to make sure it makes sense in the context of the problem.