Week 18- Top 5 Things I Learned In Pre-Calc 11

These are the top 5 things I learned this year in pre-calculus 11.
5: CDPEU
CDPEU (Can divers pee easily underwater) is a strategy I learned to easily factor equations.
C- Common (are there any common factors?). If yes, then take out the common factors.


D- Diffrence of squares (is there a difference of squares?). If yes, then you could easily factor.


P- Pattern (does it follow the pattern of x^2+x+a?). If yes then you could factor.


U- Ugly (Is it an ugly equation or can it be easily factored?), is there a coefficient in front or no? If yes then you will need a strategy, like the box method.


CDPEU is very useful and easy to remember, it will definitely help me in pre-calculus and calculus 12.
4: The Box Method
When you have reached the U part of CDPEU and you’ve determined that the quadratic equation you have is difficult to factor, the box method comes in handy.
Step one: Take the 1st term and place in the top left section of the box, place the 3rd term in the bottom right.


Step two: Multiply the two terms. Then, find two terms of the resulting product, which add up to the 2nd term.


Step three: Insert the two terms you just got into the box, the order doesn’t matter. Then find the greatest common factor of each row and each column.


Step four: combine the terms on the right into a binomial, then the terms on the bottom; you have your answer.


3: The Discriminant
The discriminant is the b^2-4ac portion of the quadratic formula. The discriminant is useful for determining the amount of solutions your quadratic equation has. You simply plug in the numbers from your quadratic equation into the discriminant and depending on the answer, you will know how many roots there are. If your answer is positive: there are 2 solutions, if the answer is 0: there is 1 solution, and if the answer is negative: there are no solutions. The discriminant is very useful, prior to solving the quadratic equation it’s always good to check the discriminant, if it’s negative, you already have your answer: there are no roots.

Step one: Identify abc values, and insert them into equation

Step two: Solve and identify how many roots there are based on the answer

2: Identifying Characteristics of a Parabola From an Equation 

When you are given a quadratic equation and are asked to graph it, it is important to know what each part of an equation means.

General Form: The General Form quadratic equation is one of the most common. The General Form equation tells you many things about a parabola. If term a of the equation is negative, you know that the equation opens down. Term c is always the Y-intercept. If there is no term c, that means the parabolas y-int is 0. If there is a middle term, that means that the parabola has moved somewhere along the a-axis (its x-int is not 0).

Standard Form: The Standard Form reveals the most important thing for graphing a quadratic equation: the vertex. P tells you the x value of the vertex, while q tells you the y value. But, when you take the p value to form the vertex, it’s sign always changes (if p was positive in the brackets, the vertex value is negative). The a value also tells you if the parabola stretches or compresses, if the a value is a>1, the parabola stretches, if 0<a<1, then the parabola compresses.

1: Changing from General Form to Standard Form

You cannot find the vertex of a parabola, just by looking at the General Form equation. So if you need to graph a parabola you must change the General Form into Standard Form. We can do this by completing the square.

Step one: Take half of the middle term, and square it. Then add the squared number to the first two terms, and subtract the squared number from the last term.

Step two: Factor what you have, and simplify. We know the vertex is at (-4,-4)

Blackout Poem – “Death of a Salesman”

This blackout poem is based on the play “Death of a Salesman”, written by Arthur Miller. This poem follows a dysfunctional family, who are struggling to make ends meet, while dealing with their own personal problems..
“Death of a Salesman” (DOAS) takes place in New York, in the late 1940s. It features Willy Loman as it’s main protagonist. Willy Loman is a failing salesman in his 60s, who’s struggling to make ends meet financially. Willy lives with his wife Linda, who is very supportive and loving of him. Willy’s two sons Happy and Biff are visiting, Willy has high expectations for his sons, which they are not meeting. Happy has a job and his own apartment, but Biff changes jobs often and does not make much money. This creates an unhealthy relationship between Biff and Willy. Willy is also struggling with his mental health, as he talks to himself often and shows signs of Alzheimer’s.
DOAS is a drama, with the sub-category of tragedy, it carries many characteristics of a tragedy. The noble hero (Willy Loman) goes through a great downfall. Willy used to be a successful salesman, with sons who had a promising future. Unfortunately, as he grew older, his sales skills deteriorated, and now he is no longer making enough money to provide for his family.
Willy’s sense of pride limits him from achieving success, when Willy’s neighbour offered him a much-needed job, Willy’s pride forced him to decline the offer.
Also, Willy made a grave mistake of having an affair with another woman. This added to his mental instability, as it constantly haunts him. It also left a lasting negative impact on Biff, who caught him having the affair. In the end, Willy goes through a revelation, when he realizes that Biff really did care for him and love him, after which he commits suicide so his family could get a sum of money from his life insurance. All of these factors make DOAS a tragedy.
The blackout poem describes Willy’s suicide. It is described through the point of view of Linda. It shows that “it was dark” (1). When Linda heard Willy speeding off in his car she knew “something [was] wrong” (4). The blackout poem also utilizes imagery to portray symbols from the play. The first line is in the shape of a 1928 Chevy. This was Willy’s former car, which he reminisces about often. The second line, is in the shape of a suitcase, this is to symbolize Willy’s profession. The third line is in the shape of a tombstone, which is to symbolizes Willy’s death, and the last line is in the shape of a pen. This is to symbolize the pen that Biff stole from his former boss, Bill Oliver. It also more deeply symbolizes Willy raising his sons poorly, as he encouraged them to steal.
This blackout poem, describes the suicide of Willy Loman, from the tragic play, “Death of a Salesman”.

DOAS Monologues

The following shows my understanding of a monologue, this is a monologue I wrote for Willy Loman from Death of a Salesman.

This is a monologue because Willy is having a long, uninterrupted conversation with another person in which he is revealing something about himself.

This monologue would fit in the current plot if Willy was to apply for financial aid.

Willy:
“I am in my 60s. I work as a traveling salesmen, and I have a loving wife who is very supportive and has lots of empathy for me. I value people-skills and wish to be well liked. I have very high hopes for my two sons, Happy and Biff. Happy is successful, but Biff cannot find his place in the world and he is not living up to my expectations, which makes me ashamed of him. Lately, my job has been taking a huge toll on my mental health. I am no longer able to financially provide for my family and I must ask my neighbour for financial support. My neighbour has been offering me a job at his business, but my pride forces me to decline his offer every time.”

Week 17- Chapter 6: Trigonometry

The focus of this week is Trigonometry.

Important terms:

Initial Arm: The arm of an angle that lies on the x-axis.

Standard position: When the initial arm is on the positive x-axis.

Terminal arm: The terminal arm is the other arm, it can be anywhere and it determines  the angle.

Refrence angle: The closest angle between the Terminal arm and the x-axis.

Coterminal: Standard angle that shares the same terminal arm as another angle.

Rotation Angle: The angle from the initial arm to the terminal arm.

Ex: 

Sine Law:

The sine law can be used to find an angle or length of a side. To find the length of a side use the top formula, to find an angle, use the bottom formula (the reciprocal). You can only use the sine law if you have both the angle and side of one of the fractions, such as angle A and side a, or angle B and side b, etc.

Cosine Law:

The cosine law can be used instead of the sine law, if there are no fractions that have a value for both the angle and the length of the side.

You can tell if you need to use sine law or cosine Law just by looking at a triangle. If there is an angle in the triangle with a side value across from it, you can use sine law. But, if the angles don’t have a side measurement across from them, you will have to use cosine law.

In this example, you can use sine law:

In this example, you have to use cosine law:

The CAST rule:

The cast rule is an easy way to remember, which trigometric ratios are positive and which are negative in every quadrant.

Updated SOH CAH TOA:

In this unit SOH CAH TOA is updated to SYR CXR and TYX. When given a (x,y) point on the terminal arm, we can determine the refrence angle using the updated SOH CAH TOA.

Week 16- Problem Solving Rational Expressions Involving Proportions

How to solve problems involving proportions:

How much lemon juice should be added to 9L water to make a lemonade that is 30% lemon juice?

Step one: Make an equation by reading the question and identifying the components of the equation.

Step two: Simplify the equation by cross-multiplying and moving all the X’s to one side.

Step three: Solve the equation by isolating the X. The answer is 27/7 Litres.

Week 15- Adding and Subtracting Rational Expressions

When adding or subtracting Rational Expressions, the denominator always has to be the same for all Expressions.

Step one: Make sure the denominator is the same by factoring both denominators and then multiplying the factors. If the two denominators have same factors, they cancel out. After you find the common denominator, you can combine the Fractions into one big fraction.

Step two: What you do to the bottom, you have to do to the top. We have to look at what could multiply 6x into 18xy, it would have to be 3y. So we multiply the numerator by 3y. Then we have to look at what multiplies 9y into 18xy, it would have to be 2x, so we multiply the numerator by 2x.

Step three: once the denominators are the same, and the numerator has been multiplied, we can combine the fractions into one big fraction, and simplify.

 

Week 13: Graphing Linead Reciprocal Functions

This week I learned about graphing reciprocal functions.

Step 1: Graph the linear function:

Step 2: Identify the asymptotes by first identifying the invariant points (the invariant points are always at the 1 and -1 y-axis points on the linear function, the asymptote goes directly through the middle of the invariant points, the other asymptote is always on the x-axis).

Step 3: Graph the hyperbolas:

Week 12: Solving Quadratic Systems of Equations

This week I learned about solving quadratic systems of equations.

A linear-quadratic system can have 3 possible solutions:

1) 2 solutions (line intersects parabola at 2 points)

2) 1 solution (Line intersects parabola at 1 point)

3) 0 solutions (line doesn’t intersect parabola)

A quadratic-quadratic system could have 4 possible solutions:

1) 2 solutions (parabolas intersect at 2 points)

2) 1 solution (parabolas intersect at 1 point)

3) 0 solutions (parabolas don’t intersect)

4) infinite solutions (parabolas are on top of one another)

How to solve a quadratic-quadratic system graphically:

Step one: Identify clues from the equations

Step two: graph the equations

Step three: Identify the intersects

The parabolas have 2 solutions (-2,-2) and (2,-2)