In an A.P prove that tm+n +tm-n =2tm

Asked by  | 12th Feb, 2010, 01:21: PM

Expert Answer:

tm+n = a + (m+n-1)d

tm-n = a + (m-n-1)d

tm+n + tm-n = a + (m+n-1)d + a + (m-n-1)d

= 2a + 2md - 2d

= 2(a+(m-1)d)

= tm

Regards,

Team,

TopperLearning.

Answered by  | 12th Feb, 2010, 05:09: PM

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