मराठी

Find the least positive integral value of n for which (1+i1−i)n is real. - Mathematics

Advertisements
Advertisements

प्रश्न

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

बेरीज
Advertisements

उत्तर

`((1+i)/(1-i))^n`

Simplify the base

`(1+i)/(1-i)`

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

(1 + i)2 = 1 + 2i + i2 = 1 + 2i − 1 = 2i

12 − i2 = 1 − (−1) = 2

`(1+i)/(1-i) = (2i)/2 = i`

`((1+i)/(1-i))^n = i^n`

Find the least positive n

n = 2

n = 4 ...

n = 2

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 13: Complex Numbers - Exercise 13.2 [पृष्ठ ३२]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 11
पाठ 13 Complex Numbers
Exercise 13.2 | Q 9 | पृष्ठ ३२

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

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

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


Evaluate: `[i^18 + (1/i)^25]^3`


Evaluate the following:

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


Evaluate the following:

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


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


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

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


Find the multiplicative inverse of the following complex number:

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


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 

Im `(1/(z_1overlinez_1))`


If \[x + iy = \frac{a + ib}{a - ib}\] prove that x2 + y2 = 1.


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

 

If \[\left( \frac{1 - i}{1 + i} \right)^{100} = a + ib\] find (a, b).


If z1z2z3 are complex numbers such that \[\left| z_1 \right| = \left| z_2 \right| = \left| z_3 \right| = \left| \frac{1}{z_1} + \frac{1}{z_2} + \frac{1}{z_3} \right| = 1\] then find the value of \[\left| z_1 + z_2 + z_3 \right|\] .


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 \[\left| z \right|\] .


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


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.


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


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


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


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


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


The value of (i5 + i6 + i7 + i8 + i9) / (1 + 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 


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

 


If the complex number \[z = x + iy\] satisfies the condition \[\left| z + 1 \right| = 1\], then z lies on


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


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)(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:

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


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 : i35 


Evaluate the following : i888 


Answer the following:

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


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


State True or False for the following:

2 is not a complex number.


Match the statements of Column A and Column B.

Column A Column B
(a) The polar form of `i + sqrt(3)` is  (i) Perpendicular bisector of
segment joining (–2, 0)
and (2, 0).
(b) The amplitude of `-1 + sqrt(-3)` is  (ii) On or outside the circle
having centre at (0, –4)
and radius 3.
(c) If |z + 2| = |z − 2|, then locus of z is (iii) `(2pi)/3`
(d) If |z + 2i| = |z − 2i|, then locus of z is (iv) Perpendicular bisector of
segment joining (0, –2) and (0, 2).
(e) Region represented by |z + 4i| ≥ 3 is  (v) `2(cos  pi/6 + i sin  pi/6)`
(f) Region represented by |z + 4| ≤ 3 is  (vi) On or inside the circle having
centre (–4, 0) and radius 3 units.
(g) Conjugate of `(1 + 2i)/(1 - i)` lies in (vii) First quadrant
(h) Reciprocal of 1 – i lies in (viii) Third quadrant

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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×