Series and Sequences statistics

For an arithmetic sequence and a geometric sequence, what does A mean?

a means the first term in a sequence

For an arithemetic sequences what is the symbol for the difference?

d

For a geometric sequence what is the symbol for the difference?

r

How do you calculate an added percentage?

1+ x/100

How do you calculate a reduced percentage?

1- x/100

When a question asks you to find the nth term, how much on day n or a value at a specific position which formula should you use? Arithmetic

tn=a+(n-1) x d

When a question asks you for a total accumulated over several terms (total) what is the formula? Arithmetic

sn= n/2 (2a + (n-1) xd)

When a question asks you to find out when a specific value is reached what formula do you use for an Arithmetic sequence?

tn= a + (n-1) x d and solve for n

When a question asks you how many terms are need to reach a total (after how many weeks will the total be x) what formula should you use? Arithmetic

sn=n/2 (2xa +(n-1) d) and ax2+bx+c=0

When a question asks you to find the nth term, how much on day n or a value at a specific position which formula should you use? Geometric

tn= a x r n-1 and solve for tn

When a question asks you for a total accumulated over several terms (total) what is the formula? Geometric

Sn= a(1-r n)/ 1-r and solve for sn

When a question asks you to find out when a specific value is reached what formula do you use for a geometric sequence?

logb(xn)=n x logb (x) solve for x

When a question asks you how many terms are need to reach a total (after how many weeks will the total be x) what formula should you use? Geometric

sn= a x (rn-1)/ r-1 then use logs to solve n=log(x)/ log(x)