Lesson Plan, Class XI (Ch-4) | Complex Numbers
LESSON PLAN MATHEMATICS
CLASS - XI
CHapter - 4 : COMPLEX NUMBERS
Rmb dav centnary public school Nawanshahr | |||||
NAME OF THE TEACHER | DINESH KUMAR | ||||
CLASS | 10+1 | CHAPTER | 04 | SUBJECT | MATHEMATICS |
TOPIC | COMPLEX NUMBERS | DURATION : 08 CLASS MEETINGS | |||
METHODOLOGY:
Lecture method and Demonstration
- Need of complex number, to be motivated by inability to solve some of the quadratic equations.
- Algebraic properties of complex numbers.
- Argand plan and modulus of complex numbers.
- Statement of fundamental theorem of algebra.
- Solution of quadratic equations (with real coefficients).
- After studying this lesson student should know
- Different types of numbers, real numbers, imaginary numbers,
- Complex numbers and the concept of iota with its values with different powers.
- Students should know the algebraic operations on the complex numbers,
- Modulus and argand plane of a complex number.
- Method of solving the quadratic equations.
- NCERT Text Book,
- NCERT Exemplar Book of mathematics,
- Worksheets , E-content, Basics and formulas from (cbsemathematics.com)
KEY WORDS
Complex Number , Real Part (Re z) , Imaginary Part (Im z) , Real Number , Imaginary Number , Pure Imaginary Number , Standard Form (a + ib) , Conjugate of a Complex Number , Modulus (|z|) , Closure Property , Commutative Property , Associative Property , Distributive Property , Argand Plane , Multiplicative Inverse.
INTRODUCTORY ACTIVITY
Also recapitulate the concept of converting degree measure into radian measure and the nature of roots of quadratic equations.
Now introduce the topic complex number and quadratic equations step by step as follows.
All rational and irrational numbers are called real numbers.
The numbers which are not real are called non real numbers. These numbers are also called imaginary numbers.
Square root of a negative real number is called the imaginary number.
Definition and introduction of complex numbers with complete explanation of its real and imaginary parts.
All real and non- real numbers are called complex number
i = √-1 , i2 = -1, i3 = - i, i4 = 1
Addition of two complex numbers
Two complex numbers are added by simply adding their real and imaginary parts
If Y = a + ib and Z = c + id then
Y + Z = (a + c) + i(b + d)
Properties of addition of two complex numbers
i) Closure Property:
Addition of two complex numbers holds the closure property. This means that addition of two complex numbers is also a complex number.
ii) Commutative Property:
Addition of complex numbers is commutative.
⇒ Y + Z = Z + Y
iii) Associative Law:
Addition of complex numbers holds associative law
⇒ (X + Y) + Z = X + (Y + Z)
iv)Existence of additive identity:
0 is the additive identity for the addition of complex number.
∵ Z + 0 = Z
v) Existence of additive inverse :
If Z is a complex number then - Z is called the additive inverse of Z.
Subtraction of two complex numbers :
Two complex numbers are subtracted by subtracting their corresponding real and imaginary parts.
If Y = a + ib, Z = c + id then
Y - Z = (a + ib) - (c + id)
= (a - c) + i(b - d)
Conjugate of a complex number
If Z= a+ib is a complex number then conjugate of Z is denoted by and is given by
Note:- Conjugate of the conjugate of complex number is the complex number itself.
If Z = a + ib, then
Modulus of complex number
If Z = a + ib is a complex number then modulus of Z is denoted by |Z| and is given by
Argand Plane :
The plane having a complex number assigned to each of its point is called a complex plan or Argand plane.
Every point of the form (x, y) can be represented in the cartesian coordinate plane.
When a complex number is represented in the plan then the plane is called a complex plane or Argand plane.
In Argand plane x- axis is called real axis and y-axis is called imaginary axis.
If Z = x + iy then
STUDENTS DELIVERABLES:
- Review questions given by the teacher.
- Students should prepare the presentation individually or in groups on the Argand plan and the representation of the complex number in the polar form.
- Solve NCERT problems with examples.
- Assignment sheet will be given as home work at the end of the topic.
- Separate sheets which will include questions of logical thinking and Higher order thinking skills will be given to the above average students.
- Class Test , Oral Test , worksheet and Assignments. can be made the part of assessment.
- Re-test(s) will be conducted on the basis of the performance of the students in the test.



Very helpful
ReplyDelete