If the `m^(t h)` term of an A.P. is `1/n` and the `n^(t h)` terms is `1/m ,` show that the sum of `m n` terms is `1/2(m m+1)dot`

Explanation

Let `a` be first term and `d` be the common difference of an `AP`

`mth` term`=1/n`

so,

`a_m​=a+(m−1)d=1/n .........(1)`

`nth` term`=1/m
`

`a_n​=a+(n−1)d=1/m ........(2)`


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