Q) If the nth term of a certain series,whose first three terms are 2,1 and -3 is of the form a+bn+c.2n ,where a,b,c are constants,then show that a,c,b are in AP.Also find the sum of first 'n' terms of the series
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62If the nth term of a certain series,whose first three terms are 2,1 and -3 is of the form a+bn+c.2n ,where a,b,c are constants,then show that a,c,b are in AP.Also find the sum of first 'n' terms of the series
T1 = a+b+2c = 2
T2 = a+2b+4c = 1
T3 = a+3b+8c = -3
Thus, b+2c=-1
and b+4c=-4
Thus, 2c=-3, c= -3/2, b=2, a = 3
I dotn see how a, c, b are in AP!
1me too........
this ws the ques u hd given in edudigm issue
put here jst to confirm if i ws nt solving properly