This week in precalc I learned that when doing absolute values if a negative number is within braces it really means its a positive absolute value. We know this because it all depends on the numbers distance from 0.

# Week 2 – Geometric Sequences (Infinite Series)

This week we were taught about geometric sequences and infinite and finite series.

Converging = finite

diverging = infinite

finite =  -1<r<1

infinite = r<-1 or r>1

Finite = sum

infinite= no sum

Equations:

$S_\infty = \frac{a}{1-r}$

# Week 1 – Arithmetic Sequence

$S_n=\frac{n}{2}(t_1+t_n)$

My arithmetic Sequence: 5, 10, 15, 20, 25

$t_1=5$ $t_{50}=?$ $S_{50}=?$

d = 5

$t_{50}=5+(50-1)5$ $t_{50}=250$

$S_{50}=\frac{50}{2}(5+50)$ $S_{50}=25(55)$

$S_{50}= 1375$ $t_{50}=250$