SELECT * FROM question_mgmt as q WHERE id=1004 AND status=1 SELECT id,question_no,question,chapter FROM question_mgmt as q WHERE courseId=2 AND subId=6 AND chapterId=80 and ex_no='2' AND status=1 ORDER BY CAST(question_no AS UNSIGNED) CBSE Free NCERT Solution of 11th mathematics Sequence and Series if the sum of n terms of an a p is pn qn2 wh

Question: If the sum of n terms of an A.P. is (pn + qn2), where p and q are constants, find the common difference

Answer:

It is known that,

\begin{align}   S_n= \frac{n}{2}\left[2a + (n-1)d\right] \end{align}

According to the given condition,

\begin{align}    \frac{n}{2}\left[2a + (n-1)d\right] = pn + qn^2 \end{align}

\begin{align}   ⇒ \frac{n}{2}\left[2a + nd-d\right] = pn + qn^2 \end{align}

\begin{align}   ⇒ na + n^2\frac{d}{2} - n.\frac{d}{2}= pn + qn^2 \end{align}

Comparing the coefficients of n2 on both sides, we obtain

\begin{align}   \frac{d}{2} = q \end{align}

\begin{align}  \therefore d = 2q \end{align}

Thus, the common difference of the A.P. is 2q.

 


< Previous Question

Next Question >

SELECT ex_no,question,question_no,id,chapter FROM question_mgmt as q WHERE courseId='2' AND subId='6' AND ex_no!=0 AND status=1 and id!=1004 ORDER BY views desc, last_viewed_on desc limit 0,10

  • Popular questions of class 11 Mathematics

SELECT ex_no,question,question_no,id,chapter FROM question_mgmt as q WHERE courseId='2' AND subId='6' AND ex_no!=0 AND status=1 and id!=1004 ORDER BY last_viewed_on desc limit 0,10

  • Recently Viewed Questions of Class 11 Mathematics

Comments

  • Answered by Ekta Mehta
  • 4 months ago

Taking Screenshots on your Samsung Galaxy M31s is very easy and quick.

  • Answered by Ekta Mehta
  • 4 months ago

Taking Screenshots on your Samsung Galaxy M31s is very easy and quick.

  • Answered by Ekta Mehta
  • 4 months ago

Taking Screenshots on your Samsung Galaxy M31s is very easy and quick.

Comment(s) on this Question


NCERT Solutions

Quick Links

Resources

Support