NCERT Class XI Mathematics - Sequences and Series - Solutions
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Question : 95
Total: 106
If a, b, c, d are in G.P., prove that ( a n + b n ) , ( b n + c n ) , ( c n + d n )
Solution:
Since a, b, c, d, are in G.P.
Then
⇒(
) n (
) n (
) n
Adding 1 to (i), we obtain
Since
Now ,
Then
⇒( b n + c n ) 2 ( a n + b n ) ( a n + c n )
Hence above equation shows that
( a n + b n ) , ( b n + c n ) , ( c n + d n )
Then
⇒
Adding 1 to (i), we obtain
Since
Now ,
Then
⇒
Hence above equation shows that
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