The concentration CCC, in mg L−1\text{mg L}^{-1}mg L−1, of a certain chemical in a reaction is modeled by the equation C=12.5e−0.8tC = 12.5 e^{-0.8t}C=12.5e−0.8t, where ttt is the time in hours after the start of the reaction. Determine the rate of change of the concentration, in mg L−1h−1\text{mg L}^{-1}\text{h}^{-1}mg L−1h−1, at the instant when the concentration is exactly 2.4 mg L−12.4 \text{ mg L}^{-1}2.4 mg L−1.
Practise Edexcel A Level Maths Differentiation with exam-style questions for A Level Maths. 311 questions covering 9.1 Differentiating sin x and cos x, 9.2 Differentiating exponentials and logarithms, 9.3 The Chain Rule, 9.4 The Product Rule, 9.5 The Quotient Rule, 9.6 Differentiating Trigonometric Functions, 9.7 Parametric Differentiation, 9.8 Implicit Differentiation, 9.9 Using Second Derivatives, and 9.10 Rates of Change, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
