Polar Representation of Complex Number on a Argand Plane Solved Problems & Solutions free pdf download

Argand Plane

We all know that the pair of numbers (x, y) can be represented on the XY plane, where x is called abscissa and y is called the ordinate. Similarly, we can represent complex numbers also on a plane called the Argand plane or complex plane. Similar to the X-axis and Y-axis in two-dimensional geometry, there are two axes in the Argand plane.

  • The axis which is horizontal is called the real axis
  • The axis which is vertical is called the imaginary axis

The complex number x+iy which corresponds to the ordered pair(x, y)is represented geometrically as the unique point (x, y) in the XY-plane.

Argand Plane

For example,

The complex number, 2+3i corresponds to the ordered pair (2, 3) geometrically.

Similarly, -3+2i corresponds to the ordered pair (-3, 2).

  • Complex numbers in the form 0+ai, where “a” is any real number will lie on the imaginary axis.
  • Complex numbers in the form a+0i, where “a” is any real number will lie on the real axis.

It is obvious that the modulus of complex number x+iy, √(x2 + y2) is the distance between the origin (0, 0) and the point (x, y).

  • The conjugate of z = x+iy is z = x-iy which is represented as (x, -y) in the Argand plane. Point (x, -y) is the mirror image of the point (x, y) across the real axis in the Argand plane.
Argand Plane -2

Example: Find the distance between the complex number z = 3 – 4i and the origin in the Argand plane.

Distance between the origin and z= 3 – 4i is equal to the modulus of z.

\(\begin{array}{l}|z|= \sqrt{3^{2}+(-4)^{2} }= \sqrt{9+16} = \sqrt{25}=5 units\end{array} \)

Polar representation of complex numbers:

Polar representation of complex numbers

Let “A” represent the non-zero complex number x + iy. OA is the directed line segment of length r and makes an angle θ with the positive direction of the X-axis.

The ordered pair (r, θ) is called the polar coordinates of point A, as the point, “A” is uniquely determined by (r, θ). The origin is called the pole and the positive X-axis is called the initial line.

Then,

x = r cosθ

y = r sinθ

We can write z = x + iy as z = r cosθ + ir sinθ = r (cosθ + i sinθ), which is called the polar form of complex number.

  • Here, r = |z| = √(x2 + y2) is the modulus of z and θ is known as the argument or amplitude of z denoted as arg z
  • For any non-zero complex number z, there corresponds to one value of θ, in the interval [0, 2π)
  • In any other interval of length 2π, for example, consider the interval -π < θ ≤ π, then the value of θ is called the principal argument of z.

Example: Represent z = √3 + i in the polar form

√3 = r cosθ

1=r sinθ

r = |z| = √(3+1)= 2

sin θ = 1/2

cos θ = √3/2

Which gives,

θ = π/6

Therefore, polar form of z is,

\(\begin{array}{l}z = 2~(cos~\left(\frac {\pi}{6} \right)~+~i~sin~\left(\frac{\pi}{6}\right))\end{array} \)

Er. Neeraj K.Anand is a freelance mentor and writer who specializes in Engineering & Science subjects. Neeraj Anand received a B.Tech degree in Electronics and Communication Engineering from N.I.T Warangal & M.Tech Post Graduation from IETE, New Delhi. He has over 30 years of teaching experience and serves as the Head of Department of ANAND CLASSES. He concentrated all his energy and experiences in academics and subsequently grew up as one of the best mentors in the country for students aspiring for success in competitive examinations. In parallel, he started a Technical Publication "ANAND TECHNICAL PUBLISHERS" in 2002 and Educational Newspaper "NATIONAL EDUCATION NEWS" in 2014 at Jalandhar. Now he is a Director of leading publication "ANAND TECHNICAL PUBLISHERS", "ANAND CLASSES" and "NATIONAL EDUCATION NEWS". He has published more than hundred books in the field of Physics, Mathematics, Computers and Information Technology. Besides this he has written many books to help students prepare for IIT-JEE and AIPMT entrance exams. He is an executive member of the IEEE (Institute of Electrical & Electronics Engineers. USA) and honorary member of many Indian scientific societies such as Institution of Electronics & Telecommunication Engineers, Aeronautical Society of India, Bioinformatics Institute of India, Institution of Engineers. He has got award from American Biographical Institute Board of International Research in the year 2005.

CBSE Class 11 Maths Syllabus for 2023-24 with Marking Scheme

CBSE syllabus for class 11 Maths is divided into 5 units. The table below shows the units, number of periods and marks allocated for maths subject. The maths theory paper is of 80 marks and the internal assessment is of 20 marks.

No.UnitsMarks
I.Sets and Functions23
II.Algebra25
III.Coordinate Geometry12
IV.Calculus08
V.Statistics and Probability12
Total Theory80
Internal Assessment20
Grand Total100

2025-26 CBSE Class 11 Maths Syllabus

Below you will find the CBSE Class Maths Syllabus for students.

Unit-I: Sets and Functions

1. Sets

Sets and their representations, empty sets, finite and infinite sets, equal sets, subsets, and subsets of a set of real numbers, especially intervals (with notations), universal set, Venn diagrams, union and intersection of sets, difference of sets, complement of a set and properties of complement.

2. Relations & Functions

Ordered pairs, Cartesian product of sets, number of elements in the Cartesian product of two finite sets, Cartesian product of the set of reals with itself (upto R x R x R), definition of relation, pictorial diagrams, domain, co-domain and range of a relation. Function as a special type of relation. Pictorial representation of a function, domain, co-domain and range of a function. Real valued functions, domain and range of these functions, constant, identity, polynomial, rational, modulus, signum, exponential, logarithmic and greatest integer functions, with their graphs. Sum, difference, product and quotients of functions.

3. Trigonometric Functions

Positive and negative angles, measuring angles in radians and in degrees and conversion from one measure to another, definition of trigonometric functions with the help of unit circle, truth of the identity, signs of trigonometric functions, domain and range of trigonometric functions and their graphs, expressing sin (x±y) and cos (x±y) in terms of sinx, siny, cosx & cosy and their simple applications.

Unit-II: Algebra

1. Complex Numbers and Quadratic Equations

Need for complex numbers, especially√−1, to be motivated by the inability to solve some of the quadratic equations. Algebraic properties of complex numbers, Argand plane.

2. Linear Inequalities

Linear inequalities, algebraic solutions of linear inequalities in one variable and their representation on the number line.

3. Permutations and Combinations

The fundamental principle of counting. Factorial n. (n!) Permutations and combinations, derivation of Formulae for nPr and nCr and their connections, simple applications.

4. Binomial Theorem

Historical perspective, statement and proof of the binomial theorem for positive integral indices, Pascal’s triangle, simple applications.

5. Sequence and Series

Sequence and series, arithmetic progression (A. P.), arithmetic mean (A.M.),  geometric progression (G.P.), general term of a G.P., sum of n terms of a G.P., infinite G.P. and its sum, geometric mean (G.M.), relation between A.M. and G.M.

Unit-III: Coordinate Geometry

1. Straight Lines

Brief recall of two-dimensional geometry from earlier classes. Slope of a line and angle between two lines. Various forms of equations of a line: parallel to axis, point-slope form, slope-intercept form, two-point form, intercept form and normal form. General equation of a line. Distance of a point from a line.

2. Conic Sections

Sections of a cone: circles, ellipse, parabola, hyperbola, a point, a straight line and a pair of intersecting lines as a degenerated case of a conic section. Standard equations and simple properties of parabola, ellipse and hyperbola. Standard equation of a circle.

3. Introduction to Three-Dimensional Geometry

Coordinate axes and coordinate planes in three dimensions. Coordinates of a point. Distance between two points.

Unit-IV: Calculus

1. Limits and Derivatives

Derivative introduced as rate of change both as that of distance function and geometrically, intuitive idea of limit, limits of polynomials and rational functions trigonometric, exponential and logarithmic functions, definition of derivative relate it to the slope of the tangent of the curve, derivative of sum, difference, product and quotient of functions. Derivatives of polynomial and trigonometric functions.

Unit-V: Statistics and Probability

1. Statistics

Measures of Dispersion: Range, mean deviation, variance and standard deviation of ungrouped/grouped data.

2. Probability

Events; occurrence of events, ‘not’, ‘and’ and ‘or’ events, exhaustive events, mutually exclusive events, Axiomatic (set theoretic) probability, connections with other theories of earlier classes. Probability of an event, probability of ‘not’, ‘and’ and ‘or’ events.

Students can also get the syllabus of all the subjects by visiting CBSE Class 11 Syllabus page. Learn Maths & Science in an interactive & fun-loving way with Anand Classes App/Tablet.

Frequently Asked Questions on CBSE Class 11 Maths Syllabus 2025-26

Q1

What is the marks distribution for internals and theory exams according to the CBSE Maths Syllabus for Class 11?

The marks distribution for internals is 20 marks and the theory exam is 80 marks based on the CBSE Class 11 Maths Syllabus.

Q2

Which is the most important chapter in the CBSE Class 11 Maths Syllabus?

The important chapter in the CBSE Class 11 Maths Syllabus is Algebra which is for 25 marks in the overall weightage.

Q3

What are the chapters covered in Unit III of the CBSE Class 11 Maths Syllabus?

The chapters covered in Unit III of the CBSE Class 11 Maths Syllabus are straight lines, conic sections and an introduction to three-dimensional geometry.