Exercise 2.7 Class 12 Math Solutions - Unit 2 Further Differentiation, Punjab Board
Step-by-step solutions to Exercise 2.7, Unit 2: Further Differentiation, for Class 12 Punjab Board students. Covers applied real-world optimization problems, formulating objective functions from geometric and economic constraints, finding critical dimensions, and verifying maxima and minima using the second derivative test, worked out question by question.
Exercise Overview
Exercise 2.7 is the grand practical application concluding Unit 2 (Further Differentiation) in Class 12 Mathematics under the Punjab Board PCTB / PECTAA curriculum. This exercise bridges pure differential calculus with real-world optimization challenges in engineering, geometry, and economics. Students apply a rigorous 7-step analytical framework: Understanding the Problem, Defining Variables, Formulating the Objective Function, Expressing Constraints, Finding Critical Points, Verifying Extrema through the Second Derivative Test, and Interpreting Physical Feasibility.
The exercise features classic optimization scenarios, including maximizing the volume of an open-top box constructed from a sheet of cardboard, minimizing the total surface area (and manufacturing material cost) of a closed cylindrical can with fixed volume, maximizing fenced rectangular areas along river boundaries, and determining optimal economic pricing for maximum profit and revenue. Every problem teaches students how to eliminate secondary variables using constraint relationships to yield a single-variable function (f(x)) suitable for differentiation.
For Punjab Board HSSC Part 2 examinations across all nine educational divisions (Lahore, Rawalpindi, Gujranwala, Faisalabad, Multan, Bahawalpur, Sargodha, Sahiwal, and D.G. Khan), Exercise 2.7 is universally recognized as one of the most prominent sources of Section C calculus Long Questions. These step-by-step solutions provide clear diagrams, explicit constraint substitutions, and complete second derivative concavity checks for every problem.