English

State true or false for the following: If a complex number coincides with its conjugate, then the number must lie on imaginary axis.

Advertisements
Advertisements

Question

State true or false for the following:

If a complex number coincides with its conjugate, then the number must lie on imaginary axis.

Options

  • True

  • False

MCQ
True or False
Advertisements

Solution

This statement is False.

Explanation:

Because x + iy = x – iy

⇒ y = 0

⇒ number lies on x-axis.

shaalaa.com
  Is there an error in this question or solution?
Chapter 5: Complex Numbers and Quadratic Equations - Solved Examples [Page 85]

APPEARS IN

NCERT Exemplar Mathematics Exemplar [English] Class 11
Chapter 5 Complex Numbers and Quadratic Equations
Solved Examples | Q 17.(iii) | Page 85

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Express the given complex number in the form a + ib: i9 + i19


Express the given complex number in the form a + ib: `(-2 - 1/3 i)^3`


Evaluate the following:

(ii) i528


Evaluate the following:

 \[\frac{1}{i^{58}}\]


Find the value of the following expression:

i5 + i10 + i15


Find the value of the following expression:

\[\frac{i^{592} + i^{590} + i^{588} + i^{586} + i^{584}}{i^{582} + i^{580} + i^{578} + i^{576} + i^{574}}\]


Find the value of the following expression:

(1 + i)6 + (1 − i)3


Express the following complex number in the standard form a + ib:

\[\frac{(2 + i )^3}{2 + 3i}\]


Express the following complex number in the standard form a + i b:

\[(1 + 2i )^{- 3}\]


Express the following complex number in the standard form a + i b:

\[\frac{5 + \sqrt{2}i}{1 - 2\sqrt{i}}\]


Find the real values of θ for which the complex number \[\frac{1 + i cos\theta}{1 - 2i cos\theta}\]  is purely real.


Find the smallest positive integer value of m for which \[\frac{(1 + i )^n}{(1 - i )^{n - 2}}\] is a real number.

 

If \[\frac{\left( 1 + i \right)^2}{2 - i} = x + iy\]  find x + y.


If \[\left( \frac{1 - i}{1 + i} \right)^{100} = a + ib\] find (a, b).


Evaluate the following:

\[2 x^3 + 2 x^2 - 7x + 72, \text { when } x = \frac{3 - 5i}{2}\]


Evaluate the following:

\[x^6 + x^4 + x^2 + 1, \text { when }x = \frac{1 + i}{\sqrt{2}}\]


What is the smallest positive integer n for which \[\left( 1 + i \right)^{2n} = \left( 1 - i \right)^{2n}\] ?


If n is any positive integer, write the value of \[\frac{i^{4n + 1} - i^{4n - 1}}{2}\].


Write 1 − i in polar form.


If\[z = \cos\frac{\pi}{4} + i \sin\frac{\pi}{6}\], then


The least positive integer n such that \[\left( \frac{2i}{1 + i} \right)^n\] is a positive integer, is.

 

\[(\sqrt{- 2})(\sqrt{- 3})\] is equal to


\[\text { If } z = \frac{1}{(2 + 3i )^2}, \text { than } \left| z \right| =\]


\[\text { If } z = \frac{1}{(1 - i)(2 + 3i)}, \text { than } \left| z \right| =\]


\[\text { If  }z = 1 - \text { cos }\theta + i \text { sin }\theta, \text { then } \left| z \right| =\]


If \[z = \frac{1}{1 - cos\theta - i sin\theta}\] then Re (z) =


If \[z = \frac{1 + 7i}{(2 - i )^2}\] , then


If the complex number \[z = x + iy\] satisfies the condition \[\left| z + 1 \right| = 1\], then z lies on


Simplify : `sqrt(-16) + 3sqrt(-25) + sqrt(-36) - sqrt(-625)`


Simplify : `4sqrt(-4) + 5sqrt(-9) - 3sqrt(-16)`


Express the following in the form of a + ib, a, b ∈ R, i = `sqrt(−1)`. State the values of a and b:

(1 + i)(1 − i)−1 


Express the following in the form of a + ib, a, b∈R i = `sqrt(−1)`. State the values of a and b:

`((1 + "i")/(1 - "i"))^2`


Evaluate the following : i888 


Evaluate the following : i–888 


Match the statements of column A and B.

Column A Column B
(a) The value of 1 + i2 + i4 + i6 + ... i20 is (i) purely imaginary complex number
(b) The value of `i^(-1097)` is (ii) purely real complex number
(c) Conjugate of 1 + i lies in (iii) second quadrant
(d) `(1 + 2i)/(1 - i)` lies in (iv) Fourth quadrant
(e) If a, b, c ∈ R and b2 – 4ac < 0, then
the roots of the equation ax2 + bx + c = 0
are non real (complex) and
(v) may not occur in conjugate pairs
(f) If a, b, c ∈ R and b2 – 4ac > 0, and
b2 – 4ac is a perfect square, then the
roots of the equation ax2 + bx + c = 0
(vi) may occur in conjugate pairs

The real value of θ for which the expression `(1 + i cos theta)/(1 - 2i cos theta)` is a real number is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×