मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता ११ वी

Answer the following: Show that z = 5(1-i)(2-i)(3-i) is purely imaginary number.

Advertisements
Advertisements

प्रश्न

Answer the following:

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

बेरीज
Advertisements

उत्तर

z = `5/((1 - "i")(2 - "i")(3 - "i"))` 

= `5/((2 - "i" - 2"i" + "i"^2)(3 - "i"))`

= `5/((2 - 3"i" - 1)(3 - "i"))`    ...[∵ i2 = – 1]

= `5/((1 - 3"i")(3 - "i"))`

= `5/(3 - "i" - 9"i" + 3"i"^2`

= `5/(3 - 10"i" - 3)`

= `5/(-10"i")`

= `(5"i")/(-10"i"^2)`

= `(5"i")/10`

= `1/2"i"`, which is a purely imaginary number.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 1: Complex Numbers - Miscellaneous Exercise 1.2 [पृष्ठ २२]

APPEARS IN

बालभारती Mathematics and Statistics (Arts and Science) Part 2 [English] Standard 11 Maharashtra State Board
पाठ 1 Complex Numbers
Miscellaneous Exercise 1.2 | Q II.08 | पृष्ठ २२

संबंधित प्रश्‍न

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


Express the given complex number in the form a + ib: `(1/5 + i 2/5) - (4 + i 5/2)`


Let z1 = 2 – i, z2 = –2 + i. Find Re`((z_1z_2)/barz_1)`


Find the value of the following expression:

i49 + i68 + i89 + i110


Find the value of the following expression:

i30 + i80 + i120


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

\[\frac{3 + 2i}{- 2 + i}\]


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

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


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

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


Find the real value of x and y, if

\[(1 + i)(x + iy) = 2 - 5i\]


If \[z_1 = 2 - i, z_2 = 1 + i,\text {  find } \left| \frac{z_1 + z_2 + 1}{z_1 - z_2 + i} \right|\]


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

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


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:

\[2 x^4 + 5 x^3 + 7 x^2 - x + 41, \text { when } x = - 2 - \sqrt{3}i\]


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


If z1 and z2 are two complex numbers such that \[\left| z_1 \right| = \left| z_2 \right|\] and arg(z1) + arg(z2) = \[\pi\] then show that \[z_1 = - \bar{{z_2}}\].


Express \[\sin\frac{\pi}{5} + i\left( 1 - \cos\frac{\pi}{5} \right)\] in polar form.


If π < θ < 2π and z = 1 + cos θ + i sin θ, then write the value of \[\left| z \right|\] .


Write the value of \[\frac{i^{592} + i^{590} + i^{588} + i^{586} + i^{584}}{i^{582} + i^{580} + i^{578} + i^{576} + i^{574}}\] .


Write the sum of the series \[i + i^2 + i^3 + . . . .\] upto 1000 terms.


For any two complex numbers z1 and z2 and any two real numbers a, b, find the value of \[\left| a z_1 - b z_2 \right|^2 + \left| a z_2 + b z_1 \right|^2\].


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


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


If θ is the amplitude of \[\frac{a + ib}{a - ib}\] , than tan θ =


The amplitude of \[\frac{1}{i}\] is equal to


The value of \[(1 + i )^4 + (1 - i )^4\] is


If \[z = a + ib\]  lies in third quadrant, then \[\frac{\bar{z}}{z}\] also lies in third quadrant if


If \[f\left( z \right) = \frac{7 - z}{1 - z^2}\] , where \[z = 1 + 2i\] then \[\left| f\left( z \right) \right|\] 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:

`(2 + sqrt(-3))/(4 + sqrt(-3))`


Evaluate the following : i888 


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


State true or false for the following:

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


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×