ICSE & CBSE Board Question Based on Arithmetic Progression of RS Aggarwal
A term of AP is given. you have to prove that the another nth term is Triple than its before nth term
This is the Question Number 18 Of Exercise 11 A of RS Aggarwal Solution.
Deepak BoraNewbie
The 4th term of an AP is Zero. Prove that its 25th term is triple its 11th term.
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Given a^4 = 0
That is (a + 3d) = 0
⇒ a = – 3d ……….. (1)
nth term of AP is given by an = a + (n – 1)d
a^11 = a + 10d = – 3d + 10d = 7d [From (1)]
a^25 = a+ 24d = – 3d + 24d = 21d [From (1)]
= 3 x 7d
Hence a^25 = 3 x a^11