Please explain how to solve this. Find an for each arithmetic sequence: a1=5; d=4; n=1

Question

Please explain how to solve this. Find an  for each arithmetic sequence: a1=5;  d=4; n=1

hartnn · Answer

general formula for an of arithmetic sequence is
$\large a_n-a_1+(n-1)d$ 
just plug in values!

hartnn · Answer

its, $\large a_n=a_1+(n-1)d$
with a1= 5, d= 4

hartnn · Answer

did you try to put a1=5,d=4 in that formula?

anonymous · Answer

is the answer 9? i'm not really sure...

hartnn · Answer

9 for what ? 
you need to find general tern $a_n$ right ? it'll be in terms of 'n' 
$\large a_n=a_1+(n-1)d \ with \: \: a_1=5,d=4, \ a_n=5+(n-1)4$

can you simplify that ?

anonymous · Answer

i'm supposed to find $$a _{n}$$

hartnn · Answer

yes, and thats what i wrote the formula for..
$a_n=a_1+(n-1)d$

hartnn · Answer

didn't you get this ? 
$\large a_n=a_1+(n-1)d \ with \: \: a_1=5,d=4, \ a_n=5+(n-1)4$

anonymous · Answer

yes, but shouldn't i substitute n with 1? is the answer 5?

hartnn · Answer

if you want to find $a_1$ from $a_n$, then you plug in n=1.
but thats not required, a1 is already given to be 5
you need to find $a_n$
which you'll get after simplifying $a_n=5+(n-1)4$

anonymous · Answer

oh, ok...