Home
Class 10
MATHS
Show that a(1), a(2),……, a(n)…. Form an ...

Show that `a_(1), a_(2)`,……, `a_(n)`…. Form an AP where `a_(n)` is defined as below:
(i) `a_(n) = 3 + 4n`, (ii) `a_(n) = 9-5n`
Also find the sum of the first 15 terms in each case.

Text Solution

Verified by Experts

The correct Answer is:
(i) 525, (ii) `- 465`
Promotional Banner

Topper's Solved these Questions

  • PROGRESSIONS

    NCERT GUJARATI|Exercise EXERCISE 6.4|4 Videos

  • PROGRESSIONS

    NCERT GUJARATI|Exercise EXERCISE 6.5|7 Videos

  • PROGRESSIONS

    NCERT GUJARATI|Exercise EXERCISE 6.2|17 Videos

  • PROBABILITY

    NCERT GUJARATI|Exercise THINK AND DISCUSS|3 Videos

  • QUADRATIC EQUATIONS

    NCERT GUJARATI|Exercise OPTIONAL EXERCISE|7 Videos

Similar Questions

Explore conceptually related problems

Show that a_(1),a_(2),......a_(n),.... from an AP where a_n is defined as below: (1)a_(n)=3+4n(2)a_(n)=9-5n Also find the sum of the first 15 terms in each case.

Let the sequence a_(n) be defined as follows: a_(1)= 1, a_(n)= a_(n-1) + 2 " for " n ge 2 . Find first five terms and write corresponding series.

What does a_(1) + a_(2) + a_(3) + …..+ a_(n) represent

For an AP, if a_(n)=4, d=2 and S_(n)= -14 , find n and a.

If a_(1),a_(2),a_(3),a_(4) and a_(5) are in AP with common difference ne 0, find the value of sum_(i=1)^(5)a_(i) " when " a_(3)=2 .

In an AP: (i) Given a=5, d=3, a_(n) = 50 , find n and S_(n) (ii) given a=7, a_(13) = 35 , find d and S_(13) . (iii) given a_(12) = 37, d=3 , find a and S_(12) (iv) given a_(3) = 15, S_(10) = 125 , find d and a_(10) (v) given a=2, d= 8, S_(n) = 90 , find n and a_(n) (vi) given a_(n) = 4, d=2, S_(n) = - 14 , find n and a. (vii) given l=28, S= 144, and there are total 9 terms, find a.

What is the 20^(th) term of the sequence defined by a_(n)= (n-1) (2-n) (3+n) ?

In an AP : Given a = 5 , d = 3 , a_(n)=50 , find n and S_n

If a_(1),a_(2),a_(3),"......" be in harmonic progression with a_(1)=5 and a_(20)=25 . The least positive integer n for which a_(n)lt0 is