Math, asked by Shreyahazra3740, 11 months ago

If the ratio of the sum of m terms and n terms of an A.p be m2 :n2, prove that the ratio of mth and nth terms is (2m_1): (2n_1).

Answers

Answered by vaishnavirekha
1

Answer:

very easy just have to equate and apply the formula s=n/2[2a+(n-1) d]

Answered by manuniyas
3

Answer:

Step-by-step explanation:

Sum of m terms of an A.P. = m/2 [2a + (m -1)d]

Sum of n terms of an A.P. = n/2 [2a + (n -1)d]

m/2 [2a + (m -1)d] / n/2 [2a + (n -1)d] = m2 : n2

⇒ [2a + md - d] / [2a + nd - d] = m/n

⇒ 2an + mnd - nd = 2am + mnd - md

⇒ 2an - 2am = nd - md

⇒ 2a (n -m) = d(n - m)

⇒ 2a = d

Ratio of m th term to n th term:

[a + (m - 1)d] / [a + (n - 1)d]

= [a + (m - 1)2a] / [a + (n - 1)2a]

= a [1 + 2m - 2] / a[1 + 2n -2]

= (2m - 1) / (2n -1)

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