English

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

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:

(2 + 3i)(2 – 3i)

Sum
Advertisements

Solution

(2 + 3i)(2 – 3i) = 4 – 9i2

= 4 – 9(– 1)    ...[∵ i2 = – 1]

= 4 + 9

= 13

∴ (2 + 3i)(2 – 3i) = 13 + 0i

∴ a = 13 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: `(5i) (- 3/5 i)`


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


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

`[(1/3 + i 7/3) + (4 + i 1/3)] -(-4/3 + i)`


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


Evaluate the following:

 \[i^{30} + i^{40} + i^{60}\]


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


Find the value of the following expression:

i49 + i68 + i89 + i110


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:

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


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

\[\frac{(1 + i)(1 + \sqrt{3}i)}{1 - i}\] .


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

\[\frac{2 + 3i}{4 + 5i}\]


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

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


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

\[\left( \frac{1}{1 - 4i} - \frac{2}{1 + i} \right)\left( \frac{3 - 4i}{5 + i} \right)\]


Find the multiplicative inverse of the following complex number:

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


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


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

 

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 −1 + \[\sqrt{3}\] in polar form .


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


Find the principal argument of \[\left( 1 + i\sqrt{3} \right)^2\] .


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


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 \[\left| z \right| = 2 \text { and } \arg\left( z \right) = \frac{\pi}{4}\],find z.


The polar form of (i25)3 is


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

 

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


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


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


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


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


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


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:

`((2 + "i"))/((3 - "i")(1 + 2"i"))`


Evaluate the following : i116 


Evaluate the following : i403 


If z1 = 3 – 2i and z2 = –1 + 3i, then Im(z1z2) = ______.


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×