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

Find the value of 1 + i2 + i4 + i6 + i8 + ... + i20 - Mathematics and Statistics

Advertisements
Advertisements

प्रश्न

Find the value of 1 + i2 + i4 + i6 + i8 + ... + i20

बेरीज
Advertisements

उत्तर

1 + i2 + i4 + i6 + i8 + ... + i20  

= 1 + (i2 + i4) + (i6 + i8) + (i10 + i12) + (i14 + i16) + (i18 + i20)

= 1 + [i2 + (i2)2] + [(i2)3 + (i2)4] + [(i2)5 + (i2)6] + [(i2)7 + (i2)8] + [(i2)9 + (i2)10]

= 1 + [–1 + (– 1)2] + [(– 1)3 + (–1)4] + [(– 1)5 + (– 1)6] + [(– 1)7 + (– 1)8] + [(– 1)9 + (– 1)10]   ...[∵ i2 = –1]

= 1 + (– 1 + 1) + (– 1 + 1) + (– 1 + 1) +  (– 1 + 1) + (– 1 + 1)

= 1 + 0 + 0 + 0 + 0 + 0

= 1

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

संबंधित प्रश्‍न

If `x – iy = sqrt((a-ib)/(c - id))` prove that `(x^2 + y^2) = (a^2 + b^2)/(c^2 + d^2)`


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


Simplify the following and express in the form a + ib:

`3 + sqrt(-64)`


Simplify the following and express in the form a + ib:

(1 + 3i)2 (3 + i)


Find the value of: x3 – 3x2 + 19x – 20, if x = 1 – 4i


Write the conjugates of the following complex number:

`-sqrt(-5)`


Write the conjugates of the following complex number:

5i


Write the conjugates of the following complex number:

`sqrt(5) - "i"`


Show that 1 + i10 + i100 − i1000 = 0 


Select the correct answer from the given alternatives:

`sqrt(-3) sqrt(-6)` is equal to


Answer the following:

Simplify the following and express in the form a + ib:

`5/2"i"(-4 - 3"i")`


Answer the following:

Simplify the following and express in the form a + ib:

`(4 + 3"i")/(1 - "i")`


Answer the following:

Solve the following equation for x, y ∈ R:

(4 − 5i)x + (2 + 3i)y = 10 − 7i


Solve the following equation for x, y ∈ R:

2x + i9y (2 + i) = xi7 + 10i16


Answer the following:

Evaluate: i131 + i49 


Answer the following:

Find the value of x4 + 9x3 + 35x2 − x + 164, if x = −5 + 4i


If z ≠ 1 and `"z"^2/("z - 1")` is real, then the point represented by the complex number z lies ______.


The argument of the complex number `(4 + 9i)/(13 + 5i)` is ______


Evaluate: (1 + i)6 + (1 – i)3 


State true or false for the following:

Multiplication of a non-zero complex number by i rotates it through a right angle in the anti-clockwise direction.


What is the principal value of amplitude of 1 – i?


The area of the triangle on the complex plane formed by the complex numbers z, –iz and z + iz is ______.


If (1 + i)z = `(1 - i)barz`, then show that z = `-ibarz`.


If z = x + iy, then show that `z  barz + 2(z + barz) + b` = 0, where b ∈ R, represents a circle.


If the real part of `(barz + 2)/(barz - 1)` is 4, then show that the locus of the point representing z in the complex plane is a circle.


The value of `sqrt(-25) xx sqrt(-9)` is ______.


If z1 and z2 are complex numbers such that z1 + z2 is a real number, then z2 = ______.


State True or False for the following:

Multiplication of a non-zero complex number by –i rotates the point about origin through a right angle in the anti-clockwise direction.


Let x, y ∈ R, then x + iy is a non-real complex number if ______.


If `(3 + i)(z + barz) - (2 + i)(z - barz) + 14i` = 0, then `barzz` is equal to ______.


If `(x + iy)^(1/5)` = a + ib, and u = `x/a - y/b`, then ______.


The smallest positive integer n for which `((1 + i)/(1 - i))^n` = –1 is ______.


If a complex number z satisfies the equation `z + sqrt(2)|z + 1| + i` = 0, then |z| is equal to ______.


If α and β are the roots of the equation x2 + 2x + 4 = 0, then `1/α^3 + 1/β^3` is equal to ______.


The complex number z = x + iy which satisfy the equation `|(z - 5i)/(z + 5i)|` = 1, lie on ______.


Simplify the following and express in the form a+ib.

`(3i^5 + 2i^7 + i^9)/(i^6 + 2i^8 + 3i^18)`


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


Find the value of `sqrt(-3) xx sqrt(-6)`


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×