Help plz!!?
write the first five terms of the seqeunce whose nth term is:
n2-5
2n2 (the 2 is sqaured by the way)
most informative answer gets my 10 points
Answers:
All you do is substitute the numbers 1 to 5 into the sequence as the first five terms means n=1..5
so n^2- 5 is:
1^2 - 5 = -4
2^2-5 = -1
3^2-5 = 4
4^2-5=11
5^2-5=20
Similary with 2*n^2 gives 2,8,18,32,50
are we doing your homework for you, or are you just curious?
Sadly I no longer have to do homework so I'm definitley not doing yours!
i hate questions with n as a variable.. i'm better with the x and y questions
substitute n=1,2,3,4,5 and get the corresponding values
(1)^2-5
(2)^2-5
(3)^2-5
4)62-5
(5)^2-5
-4,-1,4,11,20
(1)^2
(2)^2
(3)^2
(4)^2
(5)^2
2,8,18,32,50
-4 , -1, 4 , 9 , 20 ,31 45
(1) - (2) - (3) (4) (5) (6 (7)
i,e 1 (spaured) = 1 - 5 = -4
and so on
-4 , -1, 4 , 9 , 20 ,31 45
(1) - (2) - (3) (4) (5) (6 (7)
1*1 = 1 - 5 = -4
and so on
If you mean that the nth term is n squared -5 (also written as
n^2-5), then the first 5 terms are:
1^2 -5 = 1 - 5 = -4
2^2-5= 4-5 = -1
3^2-5 = 9-5 = 4
4^2-5 = 16-5 = 11
5^2-5= 25-5 = 20
don't worry these are a piece of cake...
n can represent any number.in this case it's 1,2,3,4,5,
the first equation means ( as long as it's not squared and it does mean two? if it's squared then look at the other version)
n
1x2-5 = -3
2x2-5 = -1
3x2-5 = 1
4x2-5 = 3
5x2-5 = 5
if it's n2 - 5 (squared)
1x1-5 = -4
2x2-5 = -1
3x3-5 = 4
4x4-5 = 11
5x5-5 = 20
for the second equation
2x (n x n) (do the barcket first)
2x(1x1) = 2
2x(2x2) = 8
2x(3x3) = 18
2x(4x4) = 32
2x(5x5) = 50
that takes me back, i haven't done those since gcse's good stuff - that was in 1998! - i'm 24 yrs old now!! god that makes me feel old :(
You need to re-write your question so it is more clear. The way you have this written now, it's impossible to tell whether this is a linear progression or a geometric sequence. I surmise that it is probably geometric, but I doubt you will receive many responses until you do this.
let N=nth term
for n^2-5,
n=1,N= -4
n=2,N= -1
n=3,N=4
n=4,N=11
n=5,N=20
n=n,N=n^2-5
sequence: -4,-1,4,11,20,.(n^2-5)
1st difference 3,5,7,9
2nd difference 2,2,2,
we want a formula in the form of
an^2+bn+c
N=an^2+bn+c
-4=a+b+c, (n=1)
-1=4a+2b+c, (n=2)
4=9a+3b+c, (n=3)
sweep
3=3a+b
5=5a+b
2a=2 >>>>a=1,
substitute back
b=0,c= -5
N=n^2+0n-5
=n^2-5 as required
since this is a second difference
sequence,the formula for N is a second
order polynomial,namely
n^2-5
now for 2n^2
n=1,N=2
n=2,N=8
n=3,N=18
n=4,N=32
n=5,N=50
n=n,N=2n^2
sequence:2,8,18,32,50,..(2n^2)
1st difference 6,10,14,18
2nd difference 4, 4, 4,
we want a formula in the form of
an^2+bn+c
N=an^2+bn+c
2=a+b+c, (n=1)
8=4a+2b+c, (n=2)
18=9a+3b+c, (n=3)
sweep
6=3a+b
10=5a+b
2a=4>>>>a=2
substitute back
b=0,c=0
N=2n^2+0n+0
= 2n^2 as required
since this is a second difference
sequence,the formula for N is a second
order polynomial,namely
2n^2
i hope that this increases your
knowledge of numerical analysis
where is enugu?
what is the great invention in the world history ?
Is 0 an integer?
why do i keep seeing these goddamned lights and patterns in the goddamned sky?
what is the density of water in terms of kg/m^3?
How does pregnancy affect a woman's brain?
places to shine a uv light?
Do Animals Think?
n2-5
2n2 (the 2 is sqaured by the way)
most informative answer gets my 10 points
Answers:
All you do is substitute the numbers 1 to 5 into the sequence as the first five terms means n=1..5
so n^2- 5 is:
1^2 - 5 = -4
2^2-5 = -1
3^2-5 = 4
4^2-5=11
5^2-5=20
Similary with 2*n^2 gives 2,8,18,32,50
are we doing your homework for you, or are you just curious?
Sadly I no longer have to do homework so I'm definitley not doing yours!
i hate questions with n as a variable.. i'm better with the x and y questions
substitute n=1,2,3,4,5 and get the corresponding values
(1)^2-5
(2)^2-5
(3)^2-5
4)62-5
(5)^2-5
-4,-1,4,11,20
(1)^2
(2)^2
(3)^2
(4)^2
(5)^2
2,8,18,32,50
-4 , -1, 4 , 9 , 20 ,31 45
(1) - (2) - (3) (4) (5) (6 (7)
i,e 1 (spaured) = 1 - 5 = -4
and so on
-4 , -1, 4 , 9 , 20 ,31 45
(1) - (2) - (3) (4) (5) (6 (7)
1*1 = 1 - 5 = -4
and so on
If you mean that the nth term is n squared -5 (also written as
n^2-5), then the first 5 terms are:
1^2 -5 = 1 - 5 = -4
2^2-5= 4-5 = -1
3^2-5 = 9-5 = 4
4^2-5 = 16-5 = 11
5^2-5= 25-5 = 20
don't worry these are a piece of cake...
n can represent any number.in this case it's 1,2,3,4,5,
the first equation means ( as long as it's not squared and it does mean two? if it's squared then look at the other version)
n
1x2-5 = -3
2x2-5 = -1
3x2-5 = 1
4x2-5 = 3
5x2-5 = 5
if it's n2 - 5 (squared)
1x1-5 = -4
2x2-5 = -1
3x3-5 = 4
4x4-5 = 11
5x5-5 = 20
for the second equation
2x (n x n) (do the barcket first)
2x(1x1) = 2
2x(2x2) = 8
2x(3x3) = 18
2x(4x4) = 32
2x(5x5) = 50
that takes me back, i haven't done those since gcse's good stuff - that was in 1998! - i'm 24 yrs old now!! god that makes me feel old :(
You need to re-write your question so it is more clear. The way you have this written now, it's impossible to tell whether this is a linear progression or a geometric sequence. I surmise that it is probably geometric, but I doubt you will receive many responses until you do this.
let N=nth term
for n^2-5,
n=1,N= -4
n=2,N= -1
n=3,N=4
n=4,N=11
n=5,N=20
n=n,N=n^2-5
sequence: -4,-1,4,11,20,.(n^2-5)
1st difference 3,5,7,9
2nd difference 2,2,2,
we want a formula in the form of
an^2+bn+c
N=an^2+bn+c
-4=a+b+c, (n=1)
-1=4a+2b+c, (n=2)
4=9a+3b+c, (n=3)
sweep
3=3a+b
5=5a+b
2a=2 >>>>a=1,
substitute back
b=0,c= -5
N=n^2+0n-5
=n^2-5 as required
since this is a second difference
sequence,the formula for N is a second
order polynomial,namely
n^2-5
now for 2n^2
n=1,N=2
n=2,N=8
n=3,N=18
n=4,N=32
n=5,N=50
n=n,N=2n^2
sequence:2,8,18,32,50,..(2n^2)
1st difference 6,10,14,18
2nd difference 4, 4, 4,
we want a formula in the form of
an^2+bn+c
N=an^2+bn+c
2=a+b+c, (n=1)
8=4a+2b+c, (n=2)
18=9a+3b+c, (n=3)
sweep
6=3a+b
10=5a+b
2a=4>>>>a=2
substitute back
b=0,c=0
N=2n^2+0n+0
= 2n^2 as required
since this is a second difference
sequence,the formula for N is a second
order polynomial,namely
2n^2
i hope that this increases your
knowledge of numerical analysis
The answers post by the user, for information only, UKQnA.com does not guarantee the right.