# Math Week 3 Blog Post

This week in class we learn how to make a number into an absolute value. In short, it is finding how far away from 0 a number is on a number line. when you are asked to find an entire radical you will see a number with two lines on either side of the number.

Eg. l-45l = 45

Eg. l32l = 32

If there is a minus symbol on the outside it means the radical will be negative.

Eg. -l-28l = -28

# Math 11 Edublog Post #2

This week the thing that I learned in class that I found the most interesting was how to find the sum of an infinite geometric series. For a geometric series to be infinite the common ratio (r) has to be greater than -1 and less than 1 (Ex. 0.89).

The equation to find the sum of an infinite geometric series you have to use the following equation

$a/1-r$

if we had a series with the 1st term being 3 and the difference being 0.72 then the equation would look like the following.

$3/1-0.72$

$3/-.28$

$-10.71$

# Math 11 Edublog post #1

This week I learned a lot of new things but one that stood out was finding out how to add up all the numbers in a arithmetic sequence. The formula we use is below.

$S_n=(t_1+t_n)\cdot (n\div2)$

In a sequence such as 1,3,5,7,9 to find $S_{23}$ you would have to use the above equation as well as and equation to find $t_{23}$ the solution is as follows in the picture of my work.

# Week 1 – My Arithmetic Sequence

$3,5,7,9,11,13$

$T_{50}=2\cdot49+3$

$T_{50}=101$

Last term + First term x number of terms $\div2$.

$S_{50}=(t_{50}+3)\cdot25$

$S_{50}=(101+3)\cdot25$

$S_{50}=104\cdot25$

$S_{50}=2600$