The concentration of an enzyme, EEE micromoles per litre, in a bioreactor is monitored over a 6-hour cycle. The concentration at time TTT hours, where 0≤T≤60 \le T \le 60≤T≤6, is modeled by the equation:
E=T18(9+15T−2T2)+2 E = \frac{\sqrt{T}}{18}(9 + 15T - 2T^2) + 2 E=18T(9+15T−2T2)+2Given that EEE has a stationary value at T=αT = \alphaT=α:
Use calculus to show that α\alphaα satisfies the equation
10α2−45α−9=0 10\alpha^2 - 45\alpha - 9 = 0 10α2−45α−9=0Hence find the value of α\alphaα, giving your answer to 3 decimal places.
Use further calculus to prove that EEE is a maximum at this value of α\alphaα.
717 exam-style questions on Edexcel A Level Maths Differentiation, 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. Each one has a worked solution and a mark scheme showing where the marks go.