An economist estimated that the cost function of a single-product firm is: C(Q) = 100 + 20Q + 15Q2 + 10Q3. Based on this information, determine the following: g. The marginal cost when Q = 10. When I looked this up on Chegg, it said that the answer is found in 2 steps. In step 1 a derivative is found. This is what I don't understand. The answer said that: MC (Q)=d C(Q)/dQ then it said: d(100+20Q+15Q2 + 10Q3)/dQ Then this was given: 20+30Q+30Q2 My question is.... how did they get "20+30Q+30Q2 ? Would you explain how this derivative was found in layman's terms in the most simple, step by step way possible?