copied and paste your mind (2)
jarred1eindhoven, North Brabant Netherlands114 Threads 209 Postscopied and paste your mind 
------ This thread is Archived ------
sum1 = a + a r + a r2 = 42: the sum of the three terms given, r is the common ratio.
sum2 = a2 + a2r2 + ar2r4 = 1092: the sum of the squares of the three terms given .
sum1 = a + ar + ar2 = a(r3 - 1) / (r - 1) = 42 : apply formula for a finite sum of geometric series.
sum2 = a2 + a2r2 + ar2r4 = a2(r6 - 1) / (r2 - 1) = 1092: the sum of squares is a also a sum of geometric series.
sum2/sum12 = 1092 / 422 = [ a2(r6 - 1)/(r2 - 1)] / [a2(r3 - 1)2 / (r - 1)2]
(r2 - r + 1) / (r2 + r + 1) = 1092 / 422
r = 4 , r = 1/4 : solve for r
a = 2 : substitute r = 4 and solve for a
a = 32 : substitute r = 1/4 and solve for a
a = 2 , ar = 8 , ar2 = 32 : find the three terms for r = 4
a = 32 , ar = 8 , ar2 = 2 : find the three terms for r = 1/4
sum2 = a2 + a2r2 + ar2r4 = 1092: the sum of the squares of the three terms given .
sum1 = a + ar + ar2 = a(r3 - 1) / (r - 1) = 42 : apply formula for a finite sum of geometric series.
sum2 = a2 + a2r2 + ar2r4 = a2(r6 - 1) / (r2 - 1) = 1092: the sum of squares is a also a sum of geometric series.
sum2/sum12 = 1092 / 422 = [ a2(r6 - 1)/(r2 - 1)] / [a2(r3 - 1)2 / (r - 1)2]
(r2 - r + 1) / (r2 + r + 1) = 1092 / 422
r = 4 , r = 1/4 : solve for r
a = 2 : substitute r = 4 and solve for a
a = 32 : substitute r = 1/4 and solve for a
a = 2 , ar = 8 , ar2 = 32 : find the three terms for r = 4
a = 32 , ar = 8 , ar2 = 2 : find the three terms for r = 1/4
------ This thread is Archived ------
This Thread is Archived
This Thread is archived, so you will no longer be able to post to it. Threads get archived automatically when they are older than 3 months.
« Go back to All Threads
« Go back to All Threads
More Threads
Unions support Democrats!
Ladies
Trump Elementary
The Real Stormy Story
Trump on Trial
The weird and the random facts around the world
What happened to CS while i was away.. (Long time)
Kultur-multur
One week of the most outrageous GOP leadership!
beauty of the heart
More Threads
Report threads that break rules, are offensive, or contain fighting. Staff may not be aware of the forum abuse, and cannot do anything about it unless you tell us about it. click to report forum abuse »
If one of the comments is offensive, please report the comment instead (there is a link in each comment to report it).
If one of the comments is offensive, please report the comment instead (there is a link in each comment to report it).
Stats for this Thread
769 Views
1 Comments
in Chat Threads
Created: Jul 2014
Last Viewed: Apr 22
Last Commented: Jul 2014
0 Likes