Elfrida Noviana Dewi: Reflection about English Lesson

VIDEO OF MATHEMATICS

Monday, March 11th, 2013 at D02.105. My class, Mathematics Education 2012 meet again with Mr. Marsigit. Today, he doesn’t tell us to do the quiz and we so happy to hear that. For the first time, we watch video in his lesson. There are seven videos that we watch today and all of it is about mathematics.

First video

The title of first video is about knowing math. This video is show about two mans that sing a math song in area of university. The title of the song is “What You Know about Math.” This song uses some term of mathematics in its lyric, such as trigonometry, curve, limits, log, phi, exponent, etc. And the lyric of the song are :

What you know about math?
What you know about math?
What you know about math?
Hey, don’t you know I represent Math League
when I add shorty subtract
Freshmen backpack where I’m holding all my work at

What you know about math?
What you know about math?
What you know about math?
I know all about math
Answers 44
It’s real easy cuz of sig figs
You got 45 you rounded high
Your answers too big
What you know about math?
What you know about math?
What you know about math?
I know all about math
Solar Edition you know I’m shining dawg
Extra memory, I look back to do my natural log
You know we multiply
while memorizing pi
take limits to the sky
be sure to simplify
graphing utility
that’s trinonometry
One hundred I’m math b
dont you cheat off me
distance is rate times time
the sine graph aint a line
exponential decline
but your score cant beat mine
We’re memorizing grades
for our mathly states
against the mathly greats
not getting many dates
I got to find a mate
but girls just playa hate
and always make me wait (can’t even integrate)
Dont you know I represent Math League
when I add shorty subtract
freshmen backpack where I’m holding all my work at
What you know about math?
What you know about math?
What you know about math?
I know all about math (heh)

Second video

The second video tells us about how to find the golden X. This video gives some example so we can more understand about it. From this video we could know that to find the perimeter is just dividing the equation with constant of variable.

ax = b (a and b are a constant, x is a variable)

The example :

1. 4x = 12 (get variable on side by itself)

We can divide an equation above with constant of variable. So, we divide both sides with 4 (four) and it can produce an equation

. Finally, we can find that x = 3.

But, why we can divide it by 4? Because 4 and 12 are multiples of four. So, we can substitute x = 3 at the equation and it becomes 4(3) = 12.

2. 7x = 63

By doing the same steps in the example of number 1, then we will find that x = 9. But, for this example, we don’t divide it with 4. We divide this equation with 7 because the constant of variable in this equation is 7.

3. 5x + 3 = 18

This equation is different from the previous equation. Because we just have to leave a variable at left side, so we decrease both sides with 3. This step produce 5x = 5. Then, we can divide it with constant of variable. So, we divide both sides with 5 and it can produce an equation

. Finally, we can find that x = 3.

Third video

The third video tells us about Function. In this video, function is an algebraic statement that provides a link between two or more variables. Function also relation in which each element of one set is paired with one. And there are two kinds of relation, equation (1+3 = 4) and inequalities (8 > 5).

This video also show some examples, such as :

1. y = 3x + 4

This equation can call as a function of x. And standard form from this equation is f(x) = 3x + 4. If we know value of x, we can find value of y. For example, if we know that x = 5, so we can find y = 3(5) + 4 = 19. If there is a point x, then there is a kind of y. Without x, we can’t get y.

2. g(x) = x² – 3x +2

If we know that x = 5, so we can find that g(x) = (5)² – 3(5) + 2 = 12.

Fourth video

The fourth video tells us about Degree.

This video show that degrees are one full counterclockwise rotation of terminal side of angle back to its starting point measures three hundred sixty degrees (360⁰). 360⁰ make a full circle and 1⁰ is equal to

full revolution.

This video also teaches us to convert degree become radian and vice versa. It is important for us to learn about it. The following explanation :

1 full revolution = 2π radians (remember that 1 full revolution is 360⁰)

radians (we divide two sides with 2)

radians (thenwe divide again with 180⁰)

So, we can find that

and

And now, we can try to convert 120⁰ to radians and convert

radians into degrees.

Fifth video

The fifth video tells us about Integer. Integers are like whole numbers (can’t be negative), but they also include negative numbers. Both number can’t be decimal and fraction.

So, integers can be negative {-1, -2,-3, -4, -5, … }, positive {1, 2, 3, 4, 5, … }, or zero {0}. We can put that all together like this:

Integers = { ..., -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, ... }

Picture on the side is number line. There is horizontal and vertical line that marked an even intervals or units.

A value of up and right on the number line becomes greater numbers. While, a value of down and left on the number line becomes smaller numbers. Any number above or to right of zero is positive (greater than zero). Any number below or to left of zero is negative (less than zero). Number is negative if it has a minus sign in front, such us -5. And numbers line are no end, infinity.

Digits of number are from 0 to 9. And each number represents a specific number. For example :

2 = units place 8 = thousands 5 = millions

4 = tens place 7 = ten thousands 4 = ten millions

3 = hundreds place 6 = hundred thousands

Sixth video

The sixth video tells us about Trigonometric Function. Trigonometric functions are ratios of different sides of a triangle. Trig functions only to know value of side to find measure of an angle. Figure out values of all parts of a triangle. And there are six trigonometric functions, such as sine, cosine, tangent, cosecant, secant, and cotangent. Six basic trigonometric functions defined by sides of a triangle and angle being measured.

sin θ =

csc θ =

cos θ =

sec θ =

tan θ =

cot θ =

This video also gives us an easy way to memorize three basic trigonometric functions. This method is SOH CAH TOA. SOH means that Sine obtained from Opposite side divided by Hypotenuse side. CAH means that Cosine obtained from Adjacent side divided by Hypotenuse side. And TOA means that Tangent obtained from Opposite side divide by Adjacent side.

Seventh video

The seventh video tells us about Quadrilaterals. Quadrilateral means "four sides" (quad means four, lateral means side). So, any four-sided shape is a Quadrilateral. But, the sides have to be straight, and it has to be 2-dimensional. To make a quadrilateral, we need some properties, such as four sides (or edges), four vertices (or corners), and the interior angles add up to 360 degrees. There are special types of quadrilateral :