हिंदी

Evaluate ∑n=113(in+in+1), where n ∈ N.

Advertisements
Advertisements

प्रश्न

Evaluate `sum_(n = 1)^13 (i^n + i^(n + 1))`, where n ∈ N.

योग
Advertisements

उत्तर

We have `sum_(n = 1)^13 (i^n + i^(n + 1))`

= (i + i2) + (i2 + i3) + (i3 + i4) + (i4 + i5) + (i5 + i6) + (i6 + i7) + (i7 + i8) + (i8 + i9) + (i9 + i10) + (i10 + i11) + (i11 + i12) + (i12 + i13) + (i13 + i14)

= i + 2(i2 + i3 + i4 + i5 + i6 + i7 + i8 + i9 + i10 + i11 + i12 + i13) + i14

= i + 2[–1 – i + 1 + i – 1 – i + 1 + i – 1 – i + 1 + i] + (–1)

= i + 2(0) – 1 

⇒ –1 + i

Hence, `sum_(n = 1)^13 (i^n + 1^(n + 1))` = –1 + i.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 5: Complex Numbers and Quadratic Equations - Exercise [पृष्ठ ९१]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics [English] Class 11
अध्याय 5 Complex Numbers and Quadratic Equations
Exercise | Q 2 | पृष्ठ ९१

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Find the multiplicative inverse of the complex number:

4 – 3i


If α and β are different complex numbers with |β| = 1, then find `|(beta - alpha)/(1-baralphabeta)|`


If `((1+i)/(1-i))^m` = 1, then find the least positive integral value of m.


Find the value of: 2x3 – 11x2 + 44x + 27, if x = `25/(3 - 4"i")`


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

(2i3)2 


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

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


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

`(1 + 2/i)(3 + 4/i)(5 + i)^-1`


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


Find the value of i49 + i68 + i89 + i110 


Find the value of i + i2 + i3 + i4 


Prove that `(1 + "i")^4 xx (1 + 1/"i")^4` = 16


Find the value of `("i"^6 + "i"^7 + "i"^8 + "i"^9)/("i"^2 + "i"^3)`


Find the value of x and y which satisfy the following equation (x, y∈R).

If x(1 + 3i) + y(2 − i) − 5 + i3 = 0, find x + y


Answer the following:

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

(2i3)2 


Answer the following:

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

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


Answer the following:

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

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


Answer the following:

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

`(5 + 7"i")/(4 + 3"i") + (5 + 7"i")/(4 - 3"i")`


Answer the following:

Solve the following equations for x, y ∈ R:

(x + iy) (5 + 6i) = 2 + 3i


Answer the following:

Find the value of x3 + 2x2 − 3x + 21, if x = 1 + 2i


Answer the following:

If x + iy = `("a" + "ib")/("a" - "ib")`, prove that x2 + y2 = 1


If z1 = 5 + 3i and z2 = 2 - 4i, then z1 + z2 = ______.


Locate the points for which 3 < |z| < 4.


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.


State true or false for the following:

If three complex numbers z1, z2 and z3 are in A.P., then they lie on a circle in the complex plane.


What is the reciprocal of `3 + sqrt(7)i`.


The equation |z + 1 – i| = |z – 1 + i| represents a ______.


State True or False for the following:

The inequality |z – 4| < |z – 2| represents the region given by x > 3.


If `((1 + i)/(1 - i))^x` = 1, then ______.


If z1, z2, z3 are complex numbers such that |z1| = |z2| = |z3| = `|1/z_1 + 1/z_2 + 1/z_3|` = 1, then |z1 + z2 + z3| is ______.


Let z be a complex number such that `|(z - i)/(z + 2i)|` = 1 and |z| = `5/2`. Then the value of |z + 3i| is ______.


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


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

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


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

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


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

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


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×