Basics of Complex Numbers

IMPORTANT

Basics of Complex Numbers: Overview

This topic covers concepts such as Complex Numbers, Basics of Complex Numbers, Complex Number System, Imaginary Unit iota, Power of ' i ', Square root of a Negative Real Number, Real and Imaginary Parts of a Complex Number, Argand Plane, etc.

Important Questions on Basics of Complex Numbers

EASY
IMPORTANT

The value of the sum  n=113in+in+1, where   i= 1 , equals

MEDIUM
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For positive integers  n1, n2  the value of expression 1+in1+1+i3n1+1+i5n2+1+i7n2 where  i=1 , is a real number if and only if

EASY
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Let z and  w be two non-zero complex numbers such that  z=w  and  argz+argw=π  then z equals –

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For all complex numbers   z 1 ,and    z 2  satisfying   | z 1 |=12  and   | z 2 34i |=5 respectively, the minimum value of   | z 1 z 2 |  is 

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The value of 3+i14+3i14 is -

EASY
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The value of i19+1i252 is

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If z is a complete number, then z2+z¯2=2 represents

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Represent the following complex number in the vector form in the complex plane.

-3+i

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Represent the following complex number in the vector form in the complex plane.

3+2i

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In the complex plane, let z1=3+i and z2=3-i be two adjacent vertices of an n-sided regular polygon centered at the origin. Then, n equals

EASY
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A complex number z=1+i3.

The general argument of z is

HARD
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If cosα+3cos3β+5cos5γ=0, sinα+3sin3β+5sin5γ=0 and cos3α+ 27cos9β+125cos15γ=λ2-4cos(α+3β+5γ), then λ=

MEDIUM
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1i2020+2i2021+3i2022+4i2023=

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If z1,z2 are conjugate complex numbers. Match the items under the following columns?

  Column-I   Column-II
i z1z2 a imaginary axis
ii z1+z2=0 b Im-z2
iii Imz1 c z12
iv Rez1 d Rez2

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sinπ8+icosπ88sinπ8-icosπ88=

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If 1+i1-ix=1 then

MEDIUM
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If z is a complex number of unit modulus and argument θ, then the real part of z(1-z¯)z¯(1+z) is

MEDIUM
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If z=x+iy and z-2+2 i=4 then the locus of z in the complex plane is

HARD
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The modulus amplitude form of i15 is

EASY
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If z is a purely imaginary number and Im z<0, then amp z=