Post by: wildareal on March 24, 2010, 06:59:22 pm
Post by: cltf on March 26, 2010, 08:26:59 pm
therefore: s3 = 72
therefore: 72=3/2(2x+(3-1)y)
144=6x+6y
24=x+y
therefore your middle number is 24.
hence: 24-y,24,24+y
and well the next part was really guess and check for me. I can't remember the formula.
Post by: luken93 on March 26, 2010, 09:15:55 pm
Post by: physics on March 26, 2010, 09:20:50 pm
Post by: luken93 on March 26, 2010, 09:38:10 pm
that was a uni maths question on our SAC :P i think... but i have no idea how it is related to sequecnes and series though XDyou've gotta be joking thats a uni maths question, they were the first numbers that came to mind, because i knew it had to be odd even odd and divided by 3 = 72 so i guessed those three?
surely it isn't that hard?
dont mark my words but isnt it just:
consecutive numbers
Post by: luken93 on March 26, 2010, 09:43:28 pm
The side lengths of a right-angled triangle form the successive terms of an arithmetic sequence. The perimeter of the triangle is 72m. What are the side length of the triangle?when its successive terms doesnt that mean +1? and arithmetic sequence means it is limited to + or -?
doing this chap next term, this was just my memory of year 10 further unit 2
Post by: m@tty on March 26, 2010, 09:47:03 pm
Eg. 1, 4, 6, 8, 14, 20, 234709123864716239764023875
14, 20 and 234709123864716239764023875 are consecutive terms in the sequence.
Arithmetic sequence means
EDIT:
So this problem is:
So this is the middle term, sub this into the original equation.
And now I get to the same part as the other guy....
Post by: luken93 on March 26, 2010, 09:51:48 pm
No successive terms means they follow in the series.woops haha, oh well i'll discover that next term/these holidays if i can be bothered.
Eg. 1, 4, 6, 8, 14, 20, 234709123864716239764023875
14, 20 and 234709123864716239764023875 are consecutive terms in the sequence.
Arithmetic sequence meanswhere d is any constant.
have a lot of "if i can be bothered" tasks for the holidays haha
Post by: luken93 on March 26, 2010, 09:55:06 pm
so it could be like 22/24/26 or 21/24/27 etc etc.
is there any real answer?
Post by: m@tty on March 26, 2010, 10:16:15 pm
Therefore, the numbers must form a Pythagorean triplet.
Post by: cltf on March 27, 2010, 07:22:52 am
that was a uni maths question on our SAC :P i think... but i have no idea how it is related to sequecnes and series though XDyou've gotta be joking thats a uni maths question, they were the first numbers that came to mind, because i knew it had to be odd even odd and divided by 3 = 72 so i guessed those three?
surely it isn't that hard?
dont mark my words but isnt it just:
consecutive numbers
It has to be a right angled triangle.
23,24,25 isn't a Pythagorean triad
21,24,27 isn't
22,24,26 isn't
18,24,30 is thought. - it was guess and check.
Post by: the.watchman on March 27, 2010, 10:53:34 am
Here's my solution from the spesh board:
Quote
AND,
,
So,
SO the lengths are 18m, 24m and 30m
OR to replace step 2:
Quote
AND
Post by: cltf on March 28, 2010, 12:20:31 am