# Author: Jerrico

# Desmos Holiday Card

link to see the equations and functions I used: https://www.desmos.com/calculator/wzgnsqsqzt

In this project, I had a lot of blocks because I was not sure where to start, and what to do. Then, when I went home, I saw our fireplace and the Christmas tree beside it, so I had an inspiration. My biggest challenge was the lettering, I wasn’t confident enough with the original, so I just replaced it with an image. The fireplace is the part where I’m most proud of, in a sense. I was able to make it move as if its a fire by playing around with the equation. There wasn’t really any outside help that I needed.

To make things easier for me, I copied and pasted the functions and played around with the transformations to get the end goal. This project made me understand functions and transformations better, in a way, but not completely. I haven’t really done most of the functions.

# Piece #1 – “Identities” by W.D. Valgardson

# Week 17 in Pre-Calc 11

This week, we have learned trigonometry and I will discuss one of the things I learned: the Sine Law.

It’s a very useful to solve any triangle as long as you have:

- an angle that has a side corresponding it.
- two angles / two sides / one angle and one side.

Here’s how it works: every angle needs to be written in CAPITAL LETTERS and every side needs to be written in LOWER CASE LETTERS.

angle A corresponds with side a or side BC.

angle B corresponds with side b or side AC.

angle C corresponds with side c or side AB.

what’s the formula?

if you’re finding an angle…

and if you’re finding a side…

# Nuclear Power Debate

As concerns about environment and power usage has grown, usage of nuclear power has become a controversy to many countries. Many debate to use it as continuing to use fossil fuels greatly harms our environment, and many debate not to use it as they are worried about the radiation and economic meltdown in the future as building a nuclear power plant costs billions.

My stance on this long debate is anti-nuclear. Firstly, the effects of radiation poisoning from the nuclear accidents, like the one in Chernobyl, was devastating. Other than that, the waste materials they produce emits radiation for thousands of years. And being exposed to radiation isn’t good either as we can see from the effects it brought to countries like Japan that had nuclear accidents before. For example, they couldn’t eat much food because some livestock got radiation poisoning and it can get transmitted to people if they eat them.

Also, although the power plants aren’t “emitting carbon,” the way they get their fuel, or uranium isn’t CO2-free either. In fact, uranium mines inevitably pollute our environment. Wastes they produce are very radioactive and high in temperature, harming our environment.

Furthermore, using nuclear power plants are very costly and can cost until $9 billion, and can take a long time to build. Another disadvantage is that there are finite resources that they can use and they don’t work forever. So they have to make another one again after so many years.

Other than those, having access to nuclear power is very dangerous as there are terrorist groups existing today and if they can get the information, it can get dangerous for the people as they can have nuclear power and make nuclear weapons that they can threaten the world with.

# Week 15 in PreCalc 11

One thing I’ve learned this week is about **multiplying rational expressions**.

It doesn’t really need a lot of explanation as it’s just your simple multiplying of fractions, however with variables this time.

Let’s have a recap:

We just multiply straight across, but remember we need to simplify our answer.

20/40 = 1/2

But we can also do it this way:

It’s like prime factorization method. So, you take out all of the prime factors, then just cancel out. Well, that’s exactly what we’re going to do! But let’s add variables to the fun.

So we have this not-so-pretty looking fractions and we might be thinking, how do we solve that?!

Well, I got good news! They’re pretty easy to solve as long as you’re good at factoring!

So first, factor everything.

Now that you’ve factored everything, just cancel out same factors, just like what we did earlier in that simple fraction.

Next – don’t forget about this! Remember the rule that you **cannot **have a **zero **on your denominator? This also applies to this! So, after everything’s factored out, calculate the values of *x **(or other variables) *that will result the denominator to equal zero.

Now you’re done!

If you’re wondering ‘couldn’t we have just cancel numbers out before we factor’? Take note that if numbers have +/- between them, they’re called **terms **and you **cannot **cancel them. So we factor them so we can get **factors**, which has multiplication sign between them.

**YOU CAN NOT CANCEL TERMS**

**YOU CAN ONLY CANCEL FACTORS!**

# Week 14 in Pre-Calc 11

One thing I’ve learned this week is about **reciprocal functions**. We’ve always use that word when we divided fractions. We ‘reciprocate’ the fraction we’re dividing with.

Anyways, let’s recall what a reciprocal is:

- the reciprocal of
*x*is - Basically, the reciprocal of a number is just the numerator and denominator switched.
- Remember that all whole numbers and variables are over one.
*They have a denominator of one, basically.*

What we need to remember about this topic are **asymptotes**, one’s called **vertical asymptote** (x value), one’s **horizontal asymptote **(y value). An asymptote is a line that corresponds to the zeroes of your equation.

So, let’s say we have

We must know that we cannot have a **zero on the denominator**, so we’ll first find out which value of x would result to have a zero denominator.

3x + 6 = 0

3x = -6

x = -2

Like was stated earlier, asymptotes are the zeroes to the function. So basically, since we just found out the **zero** of the denominator, we also found out one of the asymptotes. Remember, the vertical asymptote is a value of x, so our vertical asymptote is** (x=-2)**

Right now, though, we don’t need to bother with the horizontal asymptote. Take note that** if the function’s denominator is 1, our horizontal asymptote will always be zero**. (y=0)

So this is how you graph it:

- put a dashed line on where x= -2 is.
- put a dashed line on where y = 0 is.
- If the slope of your original line (3x + 6) is positive, then you will draw the
**hyperbolas**on**quadrant I and III**, and if it’s negative draw it on**quadrant II and IV.** -
*(https://www.varsitytutors.com/hotmath/hotmath_help/topics/quadrants)* - The hyperbolas must
**never touch**the asymptotes, since they are your non-permissible values. - The graph should look like this.:

# Week 13 in Pre-Calc 11

This week, I’ve learned about absolute values function on graphing.

And in this blog, I’m going to talk about how to graph an absolute value function of linear equations.

Just a recap, but we do know that for absolute values, we must remember that:

- the sum inside the absolute value symbols will
**always be positive**!

Taking the main idea that we can never get any negative answer in absolute values, since we have an equation of **y=|mx+b| **then if we graph our linear equation, we must never have any lines within the *negative y* side of the graph.

So how exactly do we graph it?

First of all, we must know what the parent function is of the graph equation we are given.

For example, we have **y = |3x + 6|**

If we take the absolute value out, we get **y = 3x + 6**

Secondly, we must figure out what the *x-intercept *is, doing it by graphing or algebraically doesn’t matter as long as we figure out what the x-intercept is accurately.

And in our equation **y = 3x + 6**, we want the y to equal zero so we could figure out our x-intercept.

In this case, it’s

0 = 3x + 6

-6 = 3x

**-2 = x**

Now that we’ve figure out what the x-intercept is, we can start graphing by taking the *y-intercept*, which is (0, 6) in our equation.

After that, make a vertical dashed line to where the x-intercept is.

Then, graph the equation without the absolute value.

Then, what you’re going to do is to make the graph “reflect” from the x-axis from where the x-intercept is. Remember that the reflected graph **HAS THE NEGATIVE SLOPE OF YOUR ORIGINAL LINE!!!**

If you’re stuck, just remember the idea of absolute value not having a negative as an answer!!

# Wave Interference Activity

**Constructive Interference **– when two crests/troughs from two sources meet, the energies combine to form a larger wave.

**Destructive Interference **– when a crest and a trough from two sources meet, the energies are against each other, leading to the waves cancel out each other.

**Standing Wave **– when two interfering waves have the same wavelength and amplitude, the result is that the interference wave pattern remains the same or stationary. The point where the wave is at rest is called a node.

# Exploring Waves

**Pulse Wave **– A single disturbance that moves from one point to another.

**Periodic Wave **– series or repeating of many disturbance at regular, even intervals.

**Transverse Waves **– the displacement of the highest point (crest), or the lowest point (trough) from the mid point of the wave is perpendicular (90° angle) to the direction the wave is travelling to.

**Longitudinal Wave **– The disturbance is in the same direction of the wave it will travel to.