Answers

2016-02-23T06:08:11+05:30
A + (p-1)d = q------------- 1
a + (q-1)d = p------------- 2
subtracting 2 from 1, we get:
[(p-1) - (q-1)]d = q-p
(p-q)d = q-p
d = -1
using  (1), a+(p-1)* -1 = q
hence, a -p+1 = q
a= q+p-1----------------------------------(3)
 now, rth term = a+(r-1)* -1
using (3), tr = q+p-1-r+1 = q+p-r
                Hence the proof...




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