Exercise 1.5 Class 12 Math Solutions - Unit 1 Graphical Representation of Functions, Punjab Board

Step-by-step solutions to Exercise 1.5, Unit 1: Graphical Representation of Functions, for Class 12 Punjab Board students. Covers real-life applications of exponential and logarithmic functions-including population growth, radioactive decay, decibel sound intensity scales, discrete compound interest, and continuous compound interest-worked out question by question.

This page provides complete solved solutions for Exercise 1.5 of Unit 1: Graphical Representation of Functions, Class 12 Mathematics, for Punjab Board (PCTB / PECTAA). Every real-life application problem is solved step by step, covering exponential growth and decay models, decibel sound intensity calculations, discrete compound interest, and continuous compounding using the base e formula for Intermediate Part 2 students.
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Exercise Overview

Exercise 1.5 concludes Unit 1 of Class 12 Mathematics by showcasing the practical applications of exponential and logarithmic functions in real-world physical, financial, and scientific scenarios under the Punjab Board PCTB / PECTAA curriculum. The exercise bridges abstract functional mathematics with applied modeling, illustrating how exponential rates govern population dynamics, bacterial growth, and radioactive decay half-life calculations through N(t) = N₀·e^(kt).

In acoustics and physics, students apply logarithmic scales to quantify sound intensity in decibels using β = 10 · log₁₀(I / I₀), learning how logarithmic compression handles vast ranges of sound power. In financial mathematics, the exercise covers discrete compound interest A = P·(1 + r/n)^(n·t) alongside continuous compound interest A = P·e^(rt). Students learn to solve for accumulation periods, effective interest yields, and doubling time by applying natural logarithms.

For Punjab Board HSSC Part 2 examinations across all nine divisions (Lahore, Rawalpindi, Gujranwala, Faisalabad, Multan, Bahawalpur, Sargodha, Sahiwal, and D.G. Khan), Exercise 1.5 is a frequent source of applied long questions and conceptual word problems. These step-by-step solutions guide students through formula selection, variable substitution, and algebraic isolation, ensuring thorough exam preparation.

FAQs

Are these Exercise 1.5 solutions according to the Punjab Board syllabus?
Yes. These solutions follow the Punjab Curriculum and Textbook Board (PCTB / PECTAA) syllabus for Class 12 Mathematics, matching the applied topics in Unit 1, Exercise 1.5 for the 2026-2027 session.
Do these solutions cover every word problem in Exercise 1.5?
Yes, all real-world word problems and numerical applications from Exercise 1.5 are included, solved step by step with clear parameter definitions and unit conversions.
Are the solutions step-by-step?
Yes. Each question details the entire mathematical model-identifying initial values, stating governing exponential or logarithmic formulas, isolating unknown rates or time variables, and evaluating final numeric solutions.
Can students read these solutions online?
Yes, the full Exercise 1.5 solution set is available to read online on this page without any download required.
Are these solutions based on the latest PCTB / PECTAA syllabus?
Yes, they are aligned with the current PCTB and PECTAA Mathematics syllabus for the 2026-2027 academic session for Class 12.
Are these solutions free for students?
Yes, Exercise 1.5 solutions on this page are completely free to read for all Class 12 students preparing for Lahore Board, Rawalpindi Board, Gujranwala Board, or any other Punjab Board examinations.