English

For a positive integer n, find the value of ( 1 − i ) n ( 1 − 1 i ) n . - Mathematics

Advertisements
Advertisements

Question

For a positive integer n, find the value of \[(1 - i )^n \left( 1 - \frac{1}{i} \right)^n\].

Solution

\[(1 - i )^n \left( 1 - \frac{1}{i} \right)^n = \left( 1 - i \right)^n \left( 1 - \frac{i^4}{i} \right)^n [ \because i^4 = 1]\]

\[ = \left( 1 - i \right)^n \left( 1 - i^3 \right)^n \]

\[ = \left( 1 - i \right)^n \left( 1 + i \right)^n [ \because i^3 = - i]\]

\[ = \left[ (1 - i)(1 + i) \right]^n \]

\[ = (1 - i^2 )^n \]

\[ = 2^n [ \because i^2 = - 1]\]

Thus, the value of 

\[(1 - i )^n \left( 1 - \frac{1}{i} \right)^n\] is 2n.

shaalaa.com
  Is there an error in this question or solution?
Chapter 13: Complex Numbers - Exercise 13.2 [Page 32]

APPEARS IN

RD Sharma Mathematics [English] Class 11
Chapter 13 Complex Numbers
Exercise 13.2 | Q 17 | Page 32

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

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


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


Evaluate the following:

\[i^{49} + i^{68} + i^{89} + i^{110}\]


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:

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


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

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


Evaluate the following:

\[2 x^3 + 2 x^2 - 7x + 72, \text { when } x = \frac{3 - 5i}{2}\]


Evaluate the following:

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


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


If z1 is a complex number other than −1 such that \[\left| z_1 \right| = 1\] and \[z_2 = \frac{z_1 - 1}{z_1 + 1}\] then show that the real parts of z2 is zero.


If \[\left| z + 1 \right| = z + 2\left( 1 + i \right)\],find z.


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


Write 1 − i in polar form.


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


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


Write the value of \[\sqrt{- 25} \times \sqrt{- 9}\].


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


The value of \[(1 + i)(1 + i^2 )(1 + i^3 )(1 + i^4 )\] is.


If z is a non-zero complex number, then \[\left| \frac{\left| z \right|^2}{zz} \right|\] is equal to


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


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


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


The complex number z which satisfies the condition \[\left| \frac{i + z}{i - z} \right| = 1\] lies on


Simplify : `4sqrt(-4) + 5sqrt(-9) - 3sqrt(-16)`


Find a and b if (a – b) + (a + b)i = a + 5i


Find a and b if `1/("a" + "ib")` = 3 – 2i


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:

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


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


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


Match the statements of column A and B.

Column A Column B
(a) The value of 1 + i2 + i4 + i6 + ... i20 is (i) purely imaginary complex number
(b) The value of `i^(-1097)` is (ii) purely real complex number
(c) Conjugate of 1 + i lies in (iii) second quadrant
(d) `(1 + 2i)/(1 - i)` lies in (iv) Fourth quadrant
(e) If a, b, c ∈ R and b2 – 4ac < 0, then
the roots of the equation ax2 + bx + c = 0
are non real (complex) and
(v) may not occur in conjugate pairs
(f) If a, b, c ∈ R and b2 – 4ac > 0, and
b2 – 4ac is a perfect square, then the
roots of the equation ax2 + bx + c = 0
(vi) may occur in conjugate pairs

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


State True or False for the following:

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


State True or False for the following:

2 is not a complex number.


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


Find the value of `(i^(592) + i^(590) + i^(588) + i^(586) + i^(584))/(i^(582) + i^(580) + i^(578) + i^(576) + i^(574))`


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×