# Week 16 : Application of Rational Equations

This week we learned about application of rational equations.

The key for this part :

First : Read the problem slowly and carefully what is being asked.
Second : Introduce a variable to represent an unknown number
Third : Write an equation the questions gave then solve
And the last one : Write anser in sentence with the unit (km/h,cm..)

Note : less than, up stream (-), greater than or added, down stream (+)

Example :

Myra takes 2 hours to plant 450 flower bulbs. Francis takes 3 hours to plant 525 flower bulbs. Working together, how long should it take them to plant 1500 bulbs?

# Week 15 : Adding and Subtracting Rational Expressions with Monomial Denominators

The strategies for adding and subtracting rational numbers can be used to add and subtarct rational expressions : write the expressions with common denominator.

For the example :

$\frac {2x}{7}\div\frac{5}{3x}$

So the non-permissible value is x = 0

A common denominator is $21x$

$\frac {2x}{7}\div\frac{5}{3x}$

= $\frac {6x^2+35}{21x}$

# Week 14 : Equivalent Rational Expression

This week we started with new chapter about rational expressions and equations.

So we will start with example so i can show you more clear about knowledge of it.

# Week 13 : Reciprocal Linear Functions

This week we learned how to graphing recipropals of Quadratic Function

So let’s see how to graph it.

# Week 11 : Solving quadratic inequalities in one variable

This week we started with new chapter: Solving quadratic inequalities in one variable. I think it same with quadratic function. So we can factor to solve it. So now let’s start with example.

Example :

2x-8>0
2x>8
x>4

4 is boundary points

# Week 10 : Review Unit Test

As I think, in all four chapters I have a clear grasp of the essential knowledge that only chapter 1: Arithmetic and Geometric Sequence. I need to review important knowledge to prepare for Unit Test.

# Week 9 : Equivalent forms

This week we learned about equivalent forms.

So In short this chapter.

We learned 3 form to write quadratic function :

First one : General form : $y=ax^2+bx+c$

Second one : Standard form : $y=a(x-q)^2+p$

And the last one : Factored form : $y=a(x-x1)(x-x2)$

Cause factored form is new one we just learned so i will introduce little bit about it.

And beside how can we change from the general from to factored or standard from. I will show you right now.

# Week 8 : Properties of Quadratic Functions

This week we started with new lesson : Graphing Quadraction Functions about the determine the value of vertex, formula, what the graph looks like and how to draw the parabola.

So let’s start the things I studies in this week :

$y=ax^2+bx+c$ : It is general form of quadratic
With a (coefficent) it will helps us know the graph will be big or small.

Also, we can know : If quadratic positive $y=x^2$ , the parabola will be go up (+) and contrast if quadratic negative $y=-x^2$ , the parabola will go down.

It will be like this in graphing:

Vertex : highest and lowest point (-1,4)

Axis of Symmetry : which the parabola is symmetric (-1) of above picture

x-intercepts : zero of function or we can determine it by Quadractic Formula

y-intercepts : it depends on c

Maximum point : when the graph opens down Because the intersection point between x and y is at the top

Minimum point : when the graph opens up so the intersection point between x and y is at the bottom

Pattern of Parent Function :

$y=x^2$ it will show stretch / compress : 1,3,5,7,9..

But if $y=2x^2$ the stretch / compress : 2,4,6,10..

Domain : the value of x and the complete set of possible values of the independent variable, make sure it is real number.

Range : the value of y

$(x-p)^2$ : depends on the value of p, It will move to right or left

Let’s star with example :

$(x+7)^2$ : when p is positive the vertex move to left
$(x-7)^2$ : when p is negative the verter move to right