English

The Value of (I5 + I6 + I7 + I8 + I9) / (1 + I) is - Mathematics

Advertisements
Advertisements

Question

The value of (i5 + i6 + i7 + i8 + i9) / (1 + i) is

Options

  • \[\frac{1}{2}(1 + i)\]

  • \[\frac{1}{2}(1 - i)\]

  • 1

  • \[\frac{1}{2}\]

MCQ

Solution

\[\frac{1}{2}(1 + i)\]

\[\frac{i^5 + i^6 + i^7 + i^8 + i^9}{1 + i}\]

\[ = \frac{i - 1 - i + 1 + i}{1 + i}\left[ \text { As,} i^5 = i, i^6 = - 1, i^7 = - i, i^8 = 1, i^9 = i \right]$\]

\[ = \frac{i}{i + 1}\]

\[ = \frac{i}{i + 1} \times \frac{i - 1}{i - 1}\]

\[ = \frac{i\left( i - 1 \right)}{i^2 - 1}\]

\[ = \frac{i^2 - i}{- 2}\]

\[ = \frac{1}{2}\left( 1 + i \right)\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 13: Complex Numbers - Exercise 13.6 [Page 66]

APPEARS IN

RD Sharma Mathematics [English] Class 11
Chapter 13 Complex Numbers
Exercise 13.6 | Q 33 | Page 66

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Express the given complex number in the form a + ib: i–39


Express the given complex number in the form a + ib: 3(7 + i7) + i(7 + i7)


Express the given complex number in the form a + ib: (1 – i) – (–1 + i6)


Evaluate: `[i^18 + (1/i)^25]^3`


Evaluate the following:

(ii) i528


Show that 1 + i10 + i20 + i30 is a real number.


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 + i b:

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


Find the real value of x and y, if

\[\frac{(1 + i)x - 2i}{3 + i} + \frac{(2 - 3i)y + i}{3 - i}\]


If \[z_1 = 2 - i, z_2 = - 2 + i,\] find 

Re \[\left( \frac{z_1 z_2}{z_1} \right)\]


If \[x + iy = \frac{a + ib}{a - ib}\] prove that x2 + y2 = 1.


If \[\left( \frac{1 + i}{1 - i} \right)^3 - \left( \frac{1 - i}{1 + i} \right)^3 = x + iy\] find (xy).


If \[a = \cos\theta + i\sin\theta\], find the value of \[\frac{1 + a}{1 - a}\].


Evaluate the following:

\[x^4 - 4 x^3 + 4 x^2 + 8x + 44,\text {  when } x = 3 + 2i\]


Evaluate the following:

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


Write the least positive integral value of n for which  \[\left( \frac{1 + i}{1 - i} \right)^n\] is real.


Find z, if \[\left| z \right| = 4 \text { and }\arg(z) = \frac{5\pi}{6} .\]


Write the value of \[\arg\left( z \right) + \arg\left( \bar{z} \right)\].


If \[\left| z + 4 \right| \leq 3\], then find the greatest and least values of \[\left| z + 1 \right|\].


Find the real value of a for which \[3 i^3 - 2a i^2 + (1 - a)i + 5\] is real.


If `(3+2i sintheta)/(1-2 i sin theta)`is a real number and 0 < θ < 2π, then θ =


If i2 = −1, then the sum i + i2 + i3 +... upto 1000 terms is equal to


If a = cos θ + i sin θ, then \[\frac{1 + a}{1 - a} =\]


The principal value of the amplitude of (1 + i) is


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


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


If \[x + iy = \frac{3 + 5i}{7 - 6i},\]  then y =


The value of \[\frac{i^{592} + i^{590} + i^{588} + i^{586} + i^{584}}{i^{582} + i^{580} + i^{578} + i^{576} + i^{574}} - 1\] is 


A real value of x satisfies the equation  \[\frac{3 - 4ix}{3 + 4ix} = a - ib (a, b \in \mathbb{R}), if a^2 + b^2 =\]


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

`("i"(4 + 3"i"))/((1 - "i"))`


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

`(4"i"^8 - 3"i"^9 + 3)/(3"i"^11 - 4"i"^10 - 2)`


Evaluate the following : i35 


Evaluate the following : i–888 


Answer the following:

Show that z = `5/((1 - "i")(2 - "i")(3 - "i"))` is purely imaginary number.


If z1 and z2 both satisfy `z + barz = 2|z - 1|` arg`(z_1 - z_2) = pi/4`, then find `"Im" (z_1 + z_2)`.


If a = cosθ + isinθ, find the value of `(1 + "a")/(1 - "a")`.


Show that `(-1+sqrt3i)^3` is a real number.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×