English

Express the following in the form of a + ib, a, b∈R i = −1. State the values of a and b: 3+2i2-5i+3-2i2+5i

Advertisements
Advertisements

Question

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

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

Sum
Advertisements

Solution

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

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

= `(6 + 15"i" + 4"i" + 10"i"^2 + 6 - 4"i" - 15"i" + 10"i"^2)/(4 - 25"i"^2)`

= `(12 + 20"i"^2)/(4 - 25"i"^2)`

= `(12 + 20(-1))/(4 -25(-1))`  ...[∵ i2 = – 1]

= `(-8)/29`

∴ `(3 + 2"i")/(2 - 5"i") + (3 - 2"i")/(2 + 5"i") = (-8)/29 + 0"i"`

∴ a = `(-8)/29` and b = 0

shaalaa.com
  Is there an error in this question or solution?
Chapter 1: Complex Numbers - Exercise 1.1 [Page 6]

RELATED QUESTIONS

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


Evaluate the following:

\[i^{37} + \frac{1}{i^{67}}\].


Find the value of the following expression:

i5 + i10 + i15


Find the value of the following expression:

1+ i2 + i4 + i6 + i8 + ... + i20


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:

\[\frac{3 - 4i}{(4 - 2i)(1 + i)}\]


Find the real value of x and y, if

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


Evaluate the following:

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


Evaluate the following:

\[x^4 + 4 x^3 + 6 x^2 + 4x + 9, \text { when } x = - 1 + i\sqrt{2}\]


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


Find the number of solutions of \[z^2 + \left| z \right|^2 = 0\].


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


Write 1 − i in polar form.


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


If \[\left| z - 5i \right| = \left| z + 5i \right|\] , then find the locus of z.


If n ∈ \[\mathbb{N}\] then find the value of \[i^n + i^{n + 1} + i^{n + 2} + i^{n + 3}\] .


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


If \[z = \frac{- 2}{1 + i\sqrt{3}}\],then the value of arg (z) is


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


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


The amplitude of \[\frac{1 + i\sqrt{3}}{\sqrt{3} + i}\] is 


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  \[\frac{3 - 4ix}{3 + 4ix} = a - ib (a, b \in \mathbb{R}), if a^2 + b^2 =\]


Which of the following is correct for any two complex numbers z1 and z2?

 


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


Find a and b if abi = 3a − b + 12i


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

(1 + i)−3 


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 : i888 


Evaluate the following : i–888 


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


State True or False for the following:

The order relation is defined on the set of complex numbers.


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


If w is a complex cube-root of unity, then prove the following

(w2 + w − 1)3 = −8


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×