Complex Numbers and Quadratic Equations Class 11 CBSE Maths Chapter 5

Class 11 CBSE Maths Syllabus
Chapter 1:Sets
Chapter 2: Relations and Functions
Chapter 3: Trigonometric Functions
Chapter 4: Principles of Mathematical Induction
Chapter 5: Complex Numbers and Quadratic Equations
Chapter 6: Linear Inequalities
Chapter 7: Permutations and Combinations
Chapter 8: Binomial Theorem
Chapter 9: Sequences and Series
Chapter 10: Straight lines
Chapter 11: Conic Sections
Chapter 12: Introduction to 3D
Chapter 13: Limits and Derivatives
Chapter 14: Mathematical Reasoning
Chapter 15: Stastics
Chapter 16: Probability

Introduction

We have provided a few important points that are covered in NCERT Class 11 Maths Chapter 5 Complex Numbers and Quadratic Equations to help students in their exam preparations. Refer to the points below:

√-1 is an imaginary quantity and is denoted by i.
i² = −1, i³ = −i, i⁴ = 1 and, i^±n = i^±k, n ∈ N where k is the remainder when n is divided by 4.
For any positive real number a, √−a = i√a.
If a, b are real numbers, then a number z = a + ib is called a complex number.
Real number a is known as the real part of z and b is known as its imaginary part. We write a = Re(z), b = lm(z).
A complex number z is purely real if lm(z) = 0 and z is purely imaginary if Re(z) = 0.
For any two complex numbers, z₁ = a₁ + ib₁ and z₂ = a₂ + ib₂.
- Addition: z₁ + z₂ = (a₁ + a₂) + i(b₁ + b₂)
- Subtraction: z₁ − z₂ = (a₁ − a₂) + i(b₁ − b₂)
- Multiplication: z₁z₂ = (a₁a₂ − b₁b₂) + i(a₁b₂ + a₂b₁)