मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता ११ वी

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

Advertisements
Advertisements

प्रश्न

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 

बेरीज
Advertisements

उत्तर

(1 + i)−3  = `1/((1 + "i")^3`

= `1/(1 + 3"i" + 3"i"^2 + "i"^3)`

= `1/(1 + 3"i" - 3 - "i")`   ...[∵  i2 = – 1, i3 = – i]

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

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

= `(-2 - 2"i")/(4 - 4"i"^2)`

= `(-2 - 2"i")/(4 + 4)`   ...[∵  i2 = – 1]

= `(-2 -2"i")/8`

= `-1/4 - 1/4 "i"`

This is of the form a + bi, where a = `-1/4` and b = `-1/4`

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 1: Complex Numbers - Exercise 1.1 [पृष्ठ ६]

APPEARS IN

संबंधित प्रश्‍न

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 – i)4


Evaluate the following:

\[\left( i^{41} + \frac{1}{i^{257}} \right)^9\]


Evaluate the following:

\[( i^{77} + i^{70} + i^{87} + i^{414} )^3\]


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


Find the value of the following expression:

i + i2 + i3 + i4


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

\[(1 + i)(1 + 2i)\]


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

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


Find the real value of x and y, if

\[(1 + i)(x + iy) = 2 - 5i\]


Find the multiplicative inverse of the following complex number:

1 − i


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


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


Write (i25)3 in polar form.


Express the following complex in the form r(cos θ + i sin θ):

 tan α − i


Express \[\sin\frac{\pi}{5} + i\left( 1 - \cos\frac{\pi}{5} \right)\] in polar form.


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 1 − i in polar form.


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


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.


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


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


If (x + iy)1/3 = a + ib, then \[\frac{x}{a} + \frac{y}{b} =\]


If \[x + iy = \frac{3 + 5i}{7 - 6i},\]  then y =


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


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


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


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


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 + sqrt(-3))/(4 + sqrt(-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)`


Find the value of `(3 + 2/i) (i^6 - i^7) (1 + i^11)`.


Evaluate the following : i888 


Evaluate the following : i93  


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

(w2 + w − 1)3 = −8


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×