Advertisements
Advertisements
Question
If \[\left( \frac{1 + i}{1 - i} \right)^3 - \left( \frac{1 - i}{1 + i} \right)^3 = x + iy\] find (x, y).
Advertisements
Solution
\[\left( \frac{1 + i}{1 - i} \right) = \frac{1 + i}{1 - i} \times \frac{1 + i}{1 + i}\]
\[ = \frac{\left( 1 + i \right)^2}{1^2 - i^2}\]
\[ = \frac{1^2 + i^2 + 2i}{1 + 1} [ \because i^2 = - 1]\]
\[ = \frac{1 - 1 + 2i}{2}\]
\[ = \frac{2i}{2}\]
\[ = i . . . . (1)\]
Also,
\[\left( \frac{1 - i}{1 + i} \right) = \frac{1 - i}{1 + i} \times \frac{1 - i}{1 - i}\]
\[ = \frac{\left( 1 - i \right)^2}{1^2 - i^2}\]
\[ = \frac{1^2 + i^2 - 2i}{1 + 1} [ \because i^2 = - 1]\]
\[ = \frac{1 - 1 - 2i}{2}\]
\[ = \frac{- 2i}{2}\]
\[ = - i . . . . (2)\]
It is given that,
\[\left( \frac{1 + i}{1 - i} \right)^3 - \left( \frac{1 - i}{1 + i} \right)^3 = x + iy\]
\[ \Rightarrow (i )^3 - ( - i )^3 = x + iy [\text {From (1) and (2)}]\]
\[ \Rightarrow i^3 + i^3 = x + iy\]
\[ \Rightarrow 2 i^3 = x + iy\]
\[ \Rightarrow 0 - 2i = x + iy [ \because i^3 = - i]\]
\[ \Rightarrow x = 0 \text { and } y = - 2\]
Thus, (x, y) = (0, −2).
APPEARS IN
RELATED QUESTIONS
Express the given complex number in the form a + ib: (1 – i)4
Evaluate: `[i^18 + (1/i)^25]^3`
Evaluate the following:
\[i^{30} + i^{40} + i^{60}\]
Evaluate the following:
\[i^{49} + i^{68} + i^{89} + i^{110}\]
Find the value of the following expression:
i49 + i68 + i89 + i110
Find the value of the following expression:
i + i2 + i3 + i4
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:
\[\frac{3 + 2i}{- 2 + i}\]
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 real value of x and y, if
\[(x + iy)(2 - 3i) = 4 + i\]
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.
If \[a = \cos\theta + i\sin\theta\], find the value of \[\frac{1 + a}{1 - a}\].
If \[\frac{z - 1}{z + 1}\] is purely imaginary number (\[z \neq - 1\]), find the value of \[\left| z \right|\].
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 \[z_1 = - \bar{{z_2}}\].
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 \[\frac{i^{4n + 1} - i^{4n - 1}}{2}\].
If \[\left| z - 5i \right| = \left| z + 5i \right|\] , then find the locus of z.
Write the value of \[\arg\left( z \right) + \arg\left( \bar{z} \right)\].
For any two complex numbers z1 and z2 and any two real numbers a, b, find the value of \[\left| a z_1 - b z_2 \right|^2 + \left| a z_2 + b z_1 \right|^2\].
Write the argument of \[\left( 1 + i\sqrt{3} \right)\left( 1 + i \right)\left( \cos\theta + i\sin\theta \right)\].
Disclaimer: There is a misprinting in the question. It should be \[\left( 1 + i\sqrt{3} \right)\] instead of \[\left( 1 + \sqrt{3} \right)\].
The argument of \[\frac{1 - i\sqrt{3}}{1 + i\sqrt{3}}\] is
\[\text { If } z = \frac{1}{(1 - i)(2 + 3i)}, \text { than } \left| z \right| =\]
If \[z = \frac{1}{1 - cos\theta - i sin\theta}\] then Re (z) =
If θ is the amplitude of \[\frac{a + ib}{a - ib}\] , than tan θ =
The value of \[(1 + i )^4 + (1 - i )^4\] is
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:
`(3 + 2"i")/(2 - 5"i") + (3 -2"i")/(2 + 5"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)−3
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)
Find the value of `(3 + 2/i) (i^6 - i^7) (1 + i^11)`.
Evaluate the following : i35
Evaluate the following : i93
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")`.
The real value of θ for which the expression `(1 + i cos theta)/(1 - 2i cos theta)` is a real number is ______.
Show that `(-1 + sqrt3 "i")^3` is a real number.
