Exercise 2.4 Class 10 Math Solutions – Unit 2 Quadratic Equations and Inequalities, Punjab Board

Step-by-step solutions to Exercise 2.4 of Unit 2: Quadratic Equations and Inequalities for Class 10 Punjab Board students. Covers calculating the discriminant (b² - 4ac) and determining the nature of roots (real, rational, irrational, equal, or imaginary) of quadratic equations.

This page provides complete solved solutions for Exercise 2.4 from Unit 2: Quadratic Equations and Inequalities, Class 10 Mathematics, Punjab Board (PCTB). It covers calculating the discriminant (b² - 4ac) of quadratic equations and examining the nature of their roots (rational, irrational, equal, or imaginary). All questions are worked out step by step for Matric Part 2 students.
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Exercise Overview

Exercise 2.4 explores the analytical core of quadratic equations in Unit 2 for Class 10 Punjab Board students. The exercise centers around the discriminant, defined algebraically as Δ = b² - 4ac from the quadratic formula for ax² + bx + c = 0. By evaluating the sign and algebraic form of the discriminant, students determine whether the roots of a quadratic equation are real, rational, irrational, equal, or complex imaginary without actually computing the roots themselves.

The exercise systematically walks students through four fundamental cases: when b² - 4ac > 0 and is a perfect square (yielding real, rational, and unequal roots); when b² - 4ac > 0 and not a perfect square (yielding real, irrational, and conjugate roots); when b² - 4ac = 0 (yielding real, rational, and coincident/equal roots); and when b² - 4ac < 0 (yielding non-real complex imaginary roots). Students also apply these criteria to evaluate unknown parameters (such as k) under given conditions, such as proving that an expression is a perfect square or has equal roots.

In Punjab Board examinations (including Lahore, Rawalpindi, Gujranwala, Faisalabad, and Multan Boards), Exercise 2.4 provides critical content for both objective MCQs and high-frequency subjective short and long questions. Board questions frequently test discriminant classification and parameter proofs. Working through these step-by-step solutions ensures students develop full mastery over discriminant theory and error-free exam execution.

FAQs

Are these Exercise 2.4 solutions according to the Punjab Board syllabus?
Yes. These solutions follow the Punjab Curriculum and Textbook Board (PCTB) syllabus for Class 10 Mathematics, matching all prescribed topics for Unit 2 Exercise 2.4 in the 2026-2027 session.
Do these solutions cover every question in Exercise 2.4?
Yes, every question in Exercise 2.4 is solved in order, detailing discriminant calculation, sign and perfect square analysis, and unknown constant evaluation.
What is the discriminant of a quadratic equation in Exercise 2.4?
The discriminant of the quadratic equation ax² + bx + c = 0 is given by the formula Disc = b² - 4ac. It determines the nature and type of the roots.
How does the discriminant determine the nature of the roots?
If Disc > 0 and a perfect square, roots are real, rational, unequal; if Disc > 0 not a perfect square, real, irrational, unequal; if Disc = 0, real, rational, equal; if Disc < 0, complex imaginary conjugates.
How do you find unknown values for equal roots in Exercise 2.4?
When roots are given as equal, set the discriminant equal to zero (b² - 4ac = 0) and solve the resulting algebraic equation for the unknown constant (e.g., k or p).
Can students read these Exercise 2.4 solutions online?
Yes, the complete solved Exercise 2.4 notes are available to read online on this page with no separate download required.
Are these solutions useful for Punjab Board exams?
Yes. Finding the discriminant, discussing the nature of roots, and proving conditions for equal roots are frequently asked short and long questions in Punjab Board papers.
Are these solutions based on the latest PCTB / PECTAA syllabus?
Yes, they are aligned with the current PCTB and PECTAA Mathematics syllabus for Class 10 for the 2026-2027 academic session.
Are these Exercise 2.4 solutions free for students?
Yes, all Exercise 2.4 solutions on MaryamNotes.pk are completely free to read online for all Class 10 students across all Punjab boards.