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Question
Following are APs or not? If they form an A.P. find the common difference d and write three more terms:
`2, 5/2, 3, 7/2 ....`
Solution
`2, 5/2, 3, 7/2 ....`
Here,
a2 - a1 = `5/2 - 2 = 1/2`
a3 - a2 = `3 - 5/2 = 1/2`
a4 - a3 = `7/2 - 3 = 1/2`
⇒ an+1 - an is same every time.
Therefore, d = `1/2` and the given numbers are in A.P.
Three more terms are
a5 = `7/2 + 1/2 = 4`
a6 = `4 + 1/2 = 9/2`
a7 = `9/2 + 1/2 = 5`
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