I am so lost I don’t even know what I am doing
#“Arithmetic” sequence
quasi sedge
Also this isn’t really a maths question but I found that paper whej I searched for a tough paper on google
It shows 6 marks so I’m guessing it’s ocr
I do edexcel
In my head maths is maths either way I’m just using these papers to prepare for the last few edexcel questions
But cos it’s diff exam board should I still do
tough peak
I am so lost I don’t even know what I am doing
you can first start to work out the nth temr of it
so
for example
5th term - 4th term = 3rd term - 2nd term
work out x
quasi sedge
so
for example
5th term - 4th term = 3rd term - 2nd term
I done 2nd - 1st = 5th - 4th because the 3rd value looks impossible
Would that still give same answer
But the problem I’m facing is in an arithmetic sequence it’s like
an + c
I got my a and c I think but idk how to show that 4x-3^2 is not a term
My a and c look horror asw idk if it’s correct
tough peak
I got my a and c I think but idk how to show that 4x-3^2 is not a term
so lets say un = 4x-3^2
Then n has to be a whole number correct?
so if you solve for n and its not an integer > 0, then its not in the sequence
so
a + (n-1)d = 4x^2 - 3
because you would have found out what x was
you know a = x+1
and you know common difference from substitution
so rewrite LHS and RHS to get rid of x as you have a value for it and solve for n
when you solve for x you should get
x = 0 or 4
use x = 4 now
alpine swallow
@quasi sedge all good?
quasi sedge
Tbh I’m still really confused
No hate to inaner I just think it’s too complicated for me to know at all
Thanks inaner for the help though
upper trellis
No hate to inaner I just think it’s too complicated for me to know at all
with an arithmetic sequence, the difference in two terms is equal to the difference in the next two terms
because it's a common difference between the terms
you have to add this d value to get to the next term
so to find d, you find the difference in the terms and equate
so 2x-(x+1)=x²-2-(2(2x+3)/6/x)
solve for x, then you can just use that value to write out the sequence
then you can work out the d value
and use that to see that 4x²-3 wouldn't work
quasi sedge
@upper trellis is arithmetic sequence the same as a geometric sequence
quasi sedge
Oh that might explain why I’m so confused
upper trellis
geometric sequence has a common ratio you times by each time to get to the next one
arithmetic sounds like addition
quasi sedge
I’ve been using principles of geometricthis whole time
upper trellis
and geometric is weird
quasi sedge
Okay that means I need to learn arithmetic sequence since I don’t remember learning it
upper trellis
yeah
quasi sedge
@upper trellis does fm and maths a level include arithmetic sequences too in more depth?
upper trellis
<@1235702017394217032> does fm and maths a level include arithmetic sequences to...
this stuff wouldn't be in gcse
not in this way anyways
there's formulas for arithmetic, and sums of series
then for geometric
you have sequence
series
and sum to infinity
minor heron
@quasi sedge can you send link to these questions? I'm tryna get an 8 🙏 or 9.
minor heron
❤️ 😍