Given the first term and the common difference of an arithmetic sequence, find the first several terms.
Add the common difference to the first term to find the second term.
Add the common difference to the second term to find the third term.
Continue until all of the desired terms are identified.
Write the terms separated by commas within brackets.
Writing terms of arithmetic sequences
Write the first five terms of the
arithmetic sequence with
${a}_{1}=17$ and
$d=-3$ .
Adding
$\text{\hspace{0.17em}}-3\text{\hspace{0.17em}}$ is the same as subtracting 3. Beginning with the first term, subtract 3 from each term to find the next term.
The first five terms are
$\text{\hspace{0.17em}}\{17,\text{\hspace{0.17em}}14,\text{\hspace{0.17em}}11,\text{\hspace{0.17em}}8,\text{\hspace{0.17em}}5\}$
Given any the first term and any other term in an arithmetic sequence, find a given term.
Substitute the values given for
${a}_{1},{a}_{n},n$ into the formula
$\text{\hspace{0.17em}}{a}_{n}={a}_{1}+(n-1)d\text{\hspace{0.17em}}$ to solve for
$\text{\hspace{0.17em}}d.$
Find a given term by substituting the appropriate values for
$\text{\hspace{0.17em}}{a}_{1},n,\text{\hspace{0.17em}}$ and
$\text{\hspace{0.17em}}d\text{\hspace{0.17em}}$ into the formula
${a}_{n}={a}_{1}+(n-1)d.$
Writing terms of arithmetic sequences
Given
${a}_{1}=8$ and
${a}_{4}=14$ , find
${a}_{5}$ .
The sequence can be written in terms of the initial term 8 and the common difference
$d$ .
$$\left\{8,8+d,8+2d,8+3d\right\}$$
We know the fourth term equals 14; we know the fourth term has the form
${a}_{1}+3d=8+3d$ .
Some arithmetic sequences are defined in terms of the previous term using a
recursive formula . The formula provides an algebraic rule for determining the terms of the sequence. A recursive formula allows us to find any term of an arithmetic sequence using a function of the preceding term. Each term is the sum of the previous term and the common difference. For example, if the common difference is 5, then each term is the previous term plus 5. As with any recursive formula, the first term must be given.
Do we have to subtract the first term from the second term to find the common difference?
No. We can subtract any term in the sequence from the subsequent term. It is, however, most common to subtract the first term from the second term because it is often the easiest method of finding the common difference.
An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
Absolutely, for me. My problems with math started in First grade...involving a nun Sister Anastasia, bad vision, talking & getting expelled from Catholic school. When it comes to math I just can't focus and all I can hear is our family silverware banging and clanging on the pink Formica table.
Carole
I'm 13 and I understand it great
AJ
I am 1 year old but I can do it! 1+1=2 proof very hard for me though.
Atone
hi
Adu
Not really they are just easy concepts which can be understood if you have great basics. I am 14 I understood them easily.
Vedant
find the 15th term of the geometric sequince whose first is 18 and last term of 387