Please explain this step by step and into the details , thanks a lot!

Consider the inverse demand function P = 680'25Q. a. Use the total differential to nd the total derivative dTR/dQ, given the denition of total revenue as TR = P0. b. Check the answer by direct substitution. c. What is the economics term for dTR/dQ? According to your answers, does it depend only on the market price? If not, what else does this term depend on? Give a verbal interpretation of your answers