NCERT Solutions Class 10 Maths Chapter 4 — Quadratic Equations#

Chapter 4 deals with quadratic equations of the form ax² + bx + c = 0. You will solve equations by factorisation and by using the quadratic formula, determine the nature of roots using the discriminant, and model real-life situations as quadratic equations.

exercise 4.1 exercise 4.2 exercise 4.3

Exercises#

  • Exercise 4.1 — Identifying quadratic equations and their standard form (2 questions)
  • Exercise 4.2 — Solving quadratic equations by factorisation (6 questions)
  • Exercise 4.3 — Nature of roots using discriminant, word problems (5 questions)

What you will learn#

  • Check whether an equation is quadratic, and write word problems as quadratic equations.
  • Solve quadratic equations by factorisation, splitting the middle term.
  • Use the discriminant to decide the nature of the roots without solving.
  • Solve word problems on areas, speeds, ages and numbers.

Key formulas and results#

  • Standard form: $ax^2 + bx + c = 0$, where $a \neq 0$.
  • Quadratic formula: $x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}$.
  • Discriminant $D = b^2 - 4ac$: two distinct real roots if $D > 0$, two equal roots if $D = 0$, no real roots if $D < 0$.

Read and revise#

Frequently asked questions#

How many exercises are in Class 10 Maths Chapter 4?
Three: Exercise 4.1 (2 questions), Exercise 4.2 (6 questions) and Exercise 4.3 (5 questions) — 13 questions in all, each solved step by step here.
What does the discriminant tell you?
Whether the equation has real roots and how many: two different ones, two equal ones, or none. It saves you from solving when the question only asks about the nature of the roots.

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