The sum of the first 21 terms of the progression _18,_18,_12 is 441
2 answers
I need the answer of the first question
but you asked no question !
You also did not say if the progression is arithmetic or geometric.
Perhaps you are looking for the missing terms??
ok then.....
looks like term(2) = 18 and term(4) = 18
If GP:
ar = 18
ar^3 = 18
divide them:
r^2 = 1
r = ± 1
if r = 1, your sequence would have all its terms alike, but it looks like 12 messes that up, so you don't have a GP
if AP:
a+d = 18
a+3d = 18
subtract them:
2d = 0
d = 0
so the common difference would be 0, and all the terms would be
the same.
Same problem!
Your problem is bogus.
You also did not say if the progression is arithmetic or geometric.
Perhaps you are looking for the missing terms??
ok then.....
looks like term(2) = 18 and term(4) = 18
If GP:
ar = 18
ar^3 = 18
divide them:
r^2 = 1
r = ± 1
if r = 1, your sequence would have all its terms alike, but it looks like 12 messes that up, so you don't have a GP
if AP:
a+d = 18
a+3d = 18
subtract them:
2d = 0
d = 0
so the common difference would be 0, and all the terms would be
the same.
Same problem!
Your problem is bogus.