हिंदी

If Z = 1 ( 2 + 3 I ) 2 , than | Z | =

Advertisements
Advertisements

प्रश्न

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

विकल्प

  • \[\frac{1}{13}\]

  • \[\frac{1}{5}\]

  • \[\frac{1}{12}\]

  • none of these

MCQ
Advertisements

उत्तर

\[\frac{1}{13}\]

\[\text { Let } z = \frac{1}{\left( 2 + 3i \right)^2}\]

\[ \Rightarrow z = \frac{1}{4 + 9 i^2 + 12i} \]

\[ \Rightarrow z = \frac{1}{4 - 9 + 12i} \]

\[ \Rightarrow z = \frac{1}{- 5 + 12i}\]

\[\Rightarrow z=\frac{1}{- 5 + 12i}\times\frac{- 5 - 12i}{- 5 - 12i}\]

\[\Rightarrow z=\frac{- 5 - 12i}{25 + 144}\]

\[ \Rightarrow z=\frac{- 5}{169}-\frac{12i}{169}\]

\[\Rightarrow\left| z \right|=\sqrt{\frac{25}{{169}^2} + \frac{144}{{169}^2}}\]

\[\Rightarrow \left| z \right|=\frac{1}{\sqrt{169}}\]

\[\Rightarrow \left| z \right| = \frac{1}{13}\]

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 13: Complex Numbers - Exercise 13.6 [पृष्ठ ६५]

APPEARS IN

आर.डी. शर्मा Mathematics [English] Class 11
अध्याय 13 Complex Numbers
Exercise 13.6 | Q 21 | पृष्ठ ६५

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Express the given complex number in the form a + ib: `(5i) (- 3/5 i)`


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


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


Express the given complex number in the form a + ib: (1 – i)4


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


Evaluate the following:

(ii) i528


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

\[(1 + i)(1 + 2i)\]


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

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


Find the real value of x and y, if

\[(x + iy)(2 - 3i) = 4 + i\]


Find the multiplicative inverse of the following complex number:

1 − i


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


If \[\left( 1 + i \right)z = \left( 1 - i \right) \bar{z}\],then show that \[z = - i \bar{z}\].


Solve the system of equations \[\text { Re }\left( z^2 \right) = 0, \left| z \right| = 2\].


Express the following complex in the form r(cos θ + i sin θ):

 tan α − i


Express the following complex in the form r(cos θ + i sin θ):

\[\frac{1 - i}{\cos\frac{\pi}{3} + i\sin\frac{\pi}{3}}\]


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


Write 1 − i in polar form.


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


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


Write the argument of \[\left( 1 + i\sqrt{3} \right)\left( 1 + i \right)\left( \cos\theta + i\sin\theta \right)\].

Disclaimer: There is a misprinting in the question. It should be  \[\left( 1 + i\sqrt{3} \right)\]  instead of \[\left( 1 + \sqrt{3} \right)\].


The polar form of (i25)3 is


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


If \[z = \left( \frac{1 + i}{1 - i} \right)\] then z4 equals


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


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


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


Find a and b if (a + ib) (1 + i) = 2 + i


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:

`("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:

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


Find the value of `(3 + 2/i) (i^6 - i^7) (1 + i^11)`.


Evaluate the following : `1/"i"^58`


Show that `(-1 + sqrt3 "i")^3` is a real number.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×