# week 11 in pc

This week in Pre Calculus 11 we learned about Graphing Linear Inequalities in two variables. The solutions to these inequalities are represented by a boundary line and shading one side of the line.

Ex:

key notes

choosing any coordinate (the easy one  is 0,0) and seeing if the statement is true or false.

# week10 in pc11

This week has been a review week.

The thing that I think are difficult is infinite geometric series.

At first I do not know what is difference between sequence and series, now I know sequence is list and series is sum .

key notes:

# week 9 in pc

Something I’ve learned this week is about domain and range.

At first I am so confused with domain and range, then I asked teacher.

that is what I learned from week 9.

# week 8 in pc

This week in pc we analyzed the quadratic function. In the equation each variable represents something that can change the graph.

positive sign, the graph moves up, negative sign, the graph moves down.

positive sign, the graph moves right, negative sign, the graph moves left.

positive sign, the graph opens up, negative sign, the graph opens down.

greater than 1, the graph is stretched vertically, between 0 and1,

the graph is compressed vertically.

# week 7 in pc11

This week we learned discriminants. A discriminant is a part of the quadratic formula and can determine the number of solutions in a quadratic equation without solving the equation.The solution(s) to a quadratic equation can be calculated using the Quadratic Formula:

The “±” means you need to do a plus AND a minus, so there are normally TWO solutions

The blue part (b2 – 4ac) is called the “discriminant”, because it can “discriminate” between the possible types of answer. If it is positive, you will get two normal solutions (two real roots), if it is zero you get just ONE solution (one root), and if it is negative you get imaginary solutions (unreal roots).

that is what I learned from week 7

# week 6 in pc11

this week we learned how to solve quadratic equation.

we had 3 ways to solve quadratic equations.

example:

Completing the square and quadratic formula can be used in any quadratic equations. Some quadratic equations cannot be solved by factoring.

that is what I learned from week 6.

# week4

What I learned this week was Radicals.

key points:

• An even exponent always gives a positive (or 0) result.
• An Even Root of a Negative Number is Not Real

.

# week 3

I learned absolute value of a real number from week 3.

key note:

the absolute value of x is always either positive or 0, but never negative.

Ex:

# week 2

the thing I learned in this week is Arithmetic sequences／series and Geometric sequences/ series.

### Key notes

• the difference between sequences and series

sequences:5,9,13,17…

series:5+9+13+17…

• importent formula

Arithmetic sequences￼￼

Arithmetic series

geometric sequences

geometric series

Example

• how to solve the Arithmetic series?

ex: Find the sum of the following arithmetic series 1,2,3…..99,100

We have a total of 100 values, so n=100.  first value is 1 and the last is 100. We plug these values into our formula, get:

• how to solve the geometric series?