हिंदी

Let < an > Be a Sequence Defined by A1 = 3 And, an = 3an − 1 + 2, for All N > 1 Find the First Four Terms of the Sequence.

Advertisements
Advertisements

प्रश्न

Let < an > be a sequence defined by a1 = 3 and, an = 3an − 1 + 2, for all n > 1
Find the first four terms of the sequence.

Advertisements

उत्तर

Given:
a1 = 3
And, an = 3an − 1 + 2 for all n > 1

\[a_2 = 3 a_{2 - 1} + 2 = 3 a_1 + 2 = 11\]

\[ a_3 = 3 a_{3 - 1} + 2 = 3 a_2 + 2 = 35\]

\[ a_4 = 3 a_{4 - 1} + 2 = 3 a_3 + 2 = 107\]

\[\text { Thus, the first four terms of the sequence are } 3, 11, 35, 107 .\]

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

In an A.P, the first term is 2 and the sum of the first five terms is one-fourth of the next five terms. Show that 20th term is –112.


The sums of n terms of two arithmetic progressions are in the ratio 5n + 4: 9n + 6. Find the ratio of their 18th terms


Insert five numbers between 8 and 26 such that the resulting sequence is an A.P.


The difference between any two consecutive interior angles of a polygon is 5°. If the smallest angle is 120°, find the number of the sides of the polygon.


Let < an > be a sequence. Write the first five term in the following:

a1 = 1, an = an − 1 + 2, n ≥ 2


Show that the following sequence is an A.P. Also find the common difference and write 3 more terms in case.

 3, −1, −5, −9 ...


Show that the following sequence is an A.P. Also find the common difference and write 3 more terms in case.

\[\sqrt{2}, 3\sqrt{2}, 5\sqrt{2}, 7\sqrt{2}, . . .\]


The nth term of a sequence is given by an = 2n2 + n + 1. Show that it is not an A.P.


Find: 

18th term of the A.P.

\[\sqrt{2}, 3\sqrt{2}, 5\sqrt{2},\]


The 6th and 17th terms of an A.P. are 19 and 41 respectively, find the 40th term.


If 9th term of an A.P. is zero, prove that its 29th term is double the 19th term.


The 10th and 18th terms of an A.P. are 41 and 73 respectively. Find 26th term.


\[\text { If } \theta_1 , \theta_2 , \theta_3 , . . . , \theta_n \text { are in AP, whose common difference is d, then show that }\]

\[\sec \theta_1 \sec \theta_2 + \sec \theta_2 \sec \theta_3 + . . . + \sec \theta_{n - 1} \sec \theta_n = \frac{\tan \theta_n - \tan \theta_1}{\sin d} \left[ NCERT \hspace{0.167em} EXEMPLAR \right]\]


Find the sum of the following arithmetic progression :

50, 46, 42, ... to 10 terms


Solve: 

1 + 4 + 7 + 10 + ... + x = 590.


How many terms are there in the A.P. whose first and fifth terms are −14 and 2 respectively and the sum of the terms is 40?


The third term of an A.P. is 7 and the seventh term exceeds three times the third term by 2. Find the first term, the common difference and the sum of first 20 terms.


The first term of an A.P. is 2 and the last term is 50. The sum of all these terms is 442. Find the common difference.


In an A.P. the first term is 2 and the sum of the first five terms is one fourth of the next five terms. Show that 20th term is −112.


Find an A.P. in which the sum of any number of terms is always three times the squared number of these terms.


If the sum of n terms of an A.P. is nP + \[\frac{1}{2}\] n (n − 1) Q, where P and Q are constants, find the common difference.


The sums of first n terms of two A.P.'s are in the ratio (7n + 2) : (n + 4). Find the ratio of their 5th terms.


If a, b, c is in A.P., then show that:

b + c − a, c + a − b, a + b − c are in A.P.


If \[\frac{b + c}{a}, \frac{c + a}{b}, \frac{a + b}{c}\] are in A.P., prove that:

\[\frac{1}{a}, \frac{1}{b}, \frac{1}{c}\] are in A.P.


If a, b, c is in A.P., prove that:

 (a − c)2 = 4 (a − b) (b − c)


A man arranges to pay off a debt of Rs 3600 by 40 annual instalments which form an arithmetic series. When 30 of the instalments are paid, he dies leaving one-third of the debt unpaid, find the value of the first instalment.


A manufacturer of radio sets produced 600 units in the third year and 700 units in the seventh year. Assuming that the product increases uniformly by a fixed number every year, find (i) the production in the first year (ii) the total product in 7 years and (iii) the product in the 10th year.


In a potato race 20 potatoes are placed in a line at intervals of 4 meters with the first potato 24 metres from the starting point. A contestant is required to bring the potatoes back to the starting place one at a time. How far would he run in bringing back all the potatoes?


If log 2, log (2x − 1) and log (2x + 3) are in A.P., write the value of x.


Sum of all two digit numbers which when divided by 4 yield unity as remainder is


Let Sn denote the sum of n terms of an A.P. whose first term is a. If the common difference d is given by d = Sn − k Sn − 1 + Sn − 2 , then k =


The first and last term of an A.P. are a and l respectively. If S is the sum of all the terms of the A.P. and the common difference is given by \[\frac{l^2 - a^2}{k - (l + a)}\] ,  then k =


If in an A.P., Sn = n2p and Sm = m2p, where Sr denotes the sum of r terms of the A.P., then Sp is equal to


Mark the correct alternative in the following question:

Let Sn denote the sum of first n terms of an A.P. If S2n = 3Sn, then S3n : Sn is equal to


If a, b, c are in G.P. and a1/x = b1/y = c1/z, then xyz are in


If a1, a2, ..., an are in A.P. with common difference d (where d ≠ 0); then the sum of the series sin d (cosec a1 cosec a2 + cosec a2 cosec a3 + ...+ cosec an–1 cosec an) is equal to cot a1 – cot an 


Let Sn denote the sum of the first n terms of an A.P. If S2n = 3Sn then S3n: Sn is equal to ______.


The fourth term of an A.P. is three times of the first term and the seventh term exceeds the twice of the third term by one, then the common difference of the progression is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×