Question

in GP why three terms that we take is different as when there is product it is a/r,a,ar ² and when it is sum it is a, ar , ar ² . in ap it is same all the time whether it is product or sum. please clarify my doubt.

Answer 1

Nice way of thinking.
by the way the answer is aimple.
which is only to do the calculations easily.
on taking products;
a/r×a×ar*2=a*3/r
ie we did delete one 'r' from it.
And equation become simple.

Also in the case of taking sum;
we take a+ar+ar*2=a(1+r+r*2)
so that we can simply add it.
if we take a/r,a,ar for this,there will be fractions when we add theese terms becouse of "a/r"

hope you understand.