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.
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.