The Total solution for NCERT class 6-12
If the sum of┬аn┬аterms of an A.P. is┬а3n2┬а+5n and its┬аmth┬аterm is 164, find the value of┬аm.
LetтАЩs consider┬аa┬аand┬аb┬аtobe the first term and the common difference of the A.P. respectively.
am┬а=┬аa┬а+ (m┬атАУ1)d┬а= 164 тАж (1)
We the sum of theterms is given by,
Sn┬а=n/2 [2a + (n-1)d]