Q. 44.3( 25 Votes )

# Show that the sequence defined byis an A.P., find its common difference.

Answer :

Put n = 1

A_{1}= 5(1) – 7

= -2

Put n = 2

A_{2}= 5(2) – 7

= 10 – 7 = 3

Put n = 3

A_{3}= 5(3) – 7

= 15 – 7 = 8

Common difference, d_{1}= a_{2} – a_{1}= 3 – (-2) = 5

Common difference, d_{2}= a_{3} – a_{2}= 8 – 3 = 5

Since, d_{1} = d_{2} and Common difference = 5

Therefore, it’s an A.P.

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