Home
Class 10
MATHS
If the sum of the first n terms of an AP...

If the sum of the first n terms of an AP is `4n-n^(2)` , what is the first term (note that the first term is `S_(1)`)? What is the sum of first two terms? What is the second term? Similarly, find the 3rd, the 10th and the nth terms

Text Solution

Verified by Experts

The correct Answer is:
`S_(1) =3, S_(2) =4; a_(2)=1; a_(3)=-1, a_(10)= -15`
`a_(n) \ 5-2n`
Promotional Banner

Topper's Solved these Questions

  • PROGRESSIONS

    NCERT BANGLISH|Exercise EXERCISE 6.4|4 Videos

  • PROGRESSIONS

    NCERT BANGLISH|Exercise EXERCISE 6.5|7 Videos

  • PROGRESSIONS

    NCERT BANGLISH|Exercise EXERCISE 6.2|17 Videos

  • PROBABILITY

    NCERT BANGLISH|Exercise THINK AND DISCUSS|3 Videos

  • QUADRATIC EQUATIONS

    NCERT BANGLISH|Exercise OPTIONAL EXERCISE|7 Videos

Similar Questions

Explore conceptually related problems

If the sum of the first 14 terms of an AP is 1050 and its first term is 10, find the 20th term.

If the sum of the first n terms of an A.P. be n^(2)+3n , which term of it has the value 162 ?

If the sum of first n terms of a series is 2n^(2) + 3n , find the series.

If the sum of the first 14 terms of an AP is 1050 and its first term is 10 , find the 20th term .

If the sum of 1st n term of an AP is n(3n + 5), find its 10th term

If the sum of first n terms of a G.P is p and the sum of the first 2n terms is 3p,show that the sum of first 3n terms is7p.

If the sum of the first n terms of a G.P. = p and the sum of the first 2n terms = 3p, show that the sum of first 3n terms = 7p.

If the sum of first n terms of an A.P. series is n^(2) +2n, then the term of the series having value 201 is-

the sum of first n terms of 1+3+7+15+31+….

If the sum of first 7 terms of an AP is 49 and that of 17 terms is 289, find the sum of first n terms.