# Tutor profile: Richard Q.

## Questions

### Subject: Music

What is the definition of harmonic progression, and could you give me examples of it?

Harmonic progression is a music terminology that is used to denote a series of chords. So, in C major for example, we could have a C-E-G chord, C-F-A chord, C-E-G chord, B-D-F-G chord, and back to C-E-G. This is a I - IV - I - V7 - I chord progression, and an example of harmonic progression.

### Subject: Calculus

Could you explain to me the concept of chain rule and any mistakes regarding its work?

Sure; chain rule is a technique used during differentiation for functions that are nested in a series of functions. For example, a function may be written as f(g(x)). For chain rule, the differentiation starts from the outer function to the inner function. Thus, the chain rule for this example function would be the derivative of f(x) (so f'(g(x)) ) multiplied by the derivative of g(x) (thus g'(x)). So, d/dx f(g(x)) = f'(g(x)) * g'(x) The most common mistake is that students forget to multiply the derivative of the inner function by the rest of the terms and/or forget to take the derivative of the inner function. It is best to show all work in this case to catch any mistakes in the process.

### Subject: ACT

Could you explain to me the answer to question 5 of the practice ACT? Everything "was subservient to the disposal" of the tides. A. NO CHANGE B. was defenseless in the face of C. depended on D. trusted in

Sure; the answer to this question is C. depended on. The reason is because after the questioned sentence, the narrator mentions how "When the tide was low, Mom could be found down on the mudflats. When the tide was high, she would be standing on the inlet bridge with her plankton net". Thus, the family, especially the mother, had their lives dictated by the tides. So we are looking for an answer that has some sort of dependence, which is C.

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