हिंदी

Find the Sum of the Following Serie to Infinity: 1 − 1 3 + 1 3 2 − 1 3 3 + 1 3 4 + . . . ∞ - Mathematics

Advertisements
Advertisements

प्रश्न

Find the sum of the following serie to infinity:

\[1 - \frac{1}{3} + \frac{1}{3^2} - \frac{1}{3^3} + \frac{1}{3^4} + . . . \infty\]

Advertisements

उत्तर

\[\text {  In the given G . P . , first term, } a = 1 \]

\[\text { and common ratio } , r = - \frac{1}{3}\]

\[\text { Hence, the sum S to infinity is given by } S = \frac{a}{1 - r} = \frac{1}{1 - \left( - \frac{1}{3} \right)} = \frac{3}{4} . \]

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 20: Geometric Progression - Exercise 20.4 [पृष्ठ ३९]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 11
अध्याय 20 Geometric Progression
Exercise 20.4 | Q 1.1 | पृष्ठ ३९

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Evaluate `sum_(k=1)^11 (2+3^k )`


If the first and the nth term of a G.P. are a ad b, respectively, and if P is the product of n terms, prove that P2 = (ab)n.


The first term of a G.P. is 1. The sum of the third term and fifth term is 90. Find the common ratio of G.P.


Find : 

nth term of the G.P.

\[\sqrt{3}, \frac{1}{\sqrt{3}}, \frac{1}{3\sqrt{3}}, . . .\]


Find the 4th term from the end of the G.P.

\[\frac{2}{27}, \frac{2}{9}, \frac{2}{3}, . . . , 162\]

Which term of the G.P. :

\[\sqrt{2}, \frac{1}{\sqrt{2}}, \frac{1}{2\sqrt{2}}, \frac{1}{4\sqrt{2}}, . . . \text { is }\frac{1}{512\sqrt{2}}?\]


The product of three numbers in G.P. is 216. If 2, 8, 6 be added to them, the results are in A.P. Find the numbers.


Find the sum of the following geometric progression:

2, 6, 18, ... to 7 terms;


Find the sum of the following geometric progression:

1, −1/2, 1/4, −1/8, ... to 9 terms;


Find the sum of the following geometric series:

 0.15 + 0.015 + 0.0015 + ... to 8 terms;


Find the sum of the following geometric series:

\[\sqrt{2} + \frac{1}{\sqrt{2}} + \frac{1}{2\sqrt{2}} + . . .\text { to 8  terms };\]


Evaluate the following:

\[\sum^{10}_{n = 2} 4^n\]


If a and b are the roots of x2 − 3x + p = 0 and c, d are the roots x2 − 12x + q = 0, where a, b, c, d form a G.P. Prove that (q + p) : (q − p) = 17 : 15.


A person has 2 parents, 4 grandparents, 8 great grandparents, and so on. Find the number of his ancestors during the ten generations preceding his own.


A G.P. consists of an even number of terms. If the sum of all the terms is 5 times the sum of the terms occupying the odd places. Find the common ratio of the G.P.


Find the sum of the terms of an infinite decreasing G.P. in which all the terms are positive, the first term is 4, and the difference between the third and fifth term is equal to 32/81.


Find the rational number whose decimal expansion is `0.4bar23`.


Find the rational numbers having the following decimal expansion: 

\[0 . 6\overline8\]


If a, b, c are in G.P., prove that:

\[\frac{(a + b + c )^2}{a^2 + b^2 + c^2} = \frac{a + b + c}{a - b + c}\]


If a, b, c are in G.P., prove that:

(a + 2b + 2c) (a − 2b + 2c) = a2 + 4c2.


If the fifth term of a G.P. is 2, then write the product of its 9 terms.


If the sum of an infinite decreasing G.P. is 3 and the sum of the squares of its term is \[\frac{9}{2}\], then write its first term and common difference.


The sum of an infinite G.P. is 4 and the sum of the cubes of its terms is 92. The common ratio of the original G.P. is 


The product (32), (32)1/6 (32)1/36 ... to ∞ is equal to 


In a G.P. if the (m + n)th term is p and (m − n)th term is q, then its mth term is 


Check whether the following sequence is G.P. If so, write tn.

`sqrt(5), 1/sqrt(5), 1/(5sqrt(5)), 1/(25sqrt(5))`, ...


Find three numbers in G.P. such that their sum is 21 and sum of their squares is 189.


The numbers 3, x, and x + 6 form are in G.P. Find 20th term.


The numbers 3, x, and x + 6 form are in G.P. Find nth term


For the following G.P.s, find Sn

0.7, 0.07, 0.007, .....


Find: `sum_("r" = 1)^10(3 xx 2^"r")`


The value of a house appreciates 5% per year. How much is the house worth after 6 years if its current worth is ₹ 15 Lac. [Given: (1.05)5 = 1.28, (1.05)6 = 1.34]


Express the following recurring decimal as a rational number:

`2.bar(4)`


Express the following recurring decimal as a rational number:

`51.0bar(2)`


If the common ratio of a G.P. is `2/3` and sum to infinity is 12. Find the first term


Find : `sum_("r" = 1)^oo 4(0.5)^"r"`


Select the correct answer from the given alternative.

Which term of the geometric progression 1, 2, 4, 8, ... is 2048


Answer the following:

For a sequence , if tn = `(5^("n" - 2))/(7^("n" - 3))`, verify whether the sequence is a G.P. If it is a G.P., find its first term and the common ratio.


Answer the following:

Find five numbers in G.P. such that their product is 243 and sum of second and fourth number is 10.


For a, b, c to be in G.P. the value of `(a - b)/(b - c)` is equal to ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×