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Monday, February 24, 2014

I/D #1: Unit N: Concept 7: How do special right triangles and the unit circle compare?

1. The 30* Triangle
The 30* triangle has three different sides to it: adjacent which is x, opposite which is y, and hypotenuse which is r. The side opposite the hypotenuse will always be x.The hypotenuse must be one if you want to derive the unit circle from the triangle. If you want this to happen you have to divide each side by 2x. Once you do this you will get x=radical 3 divided by 2, y=1/2 and r=1. We can use these simplified values as coordinates to determine where 30 degrees lies in a quadrant on the unit circle. We know that 30 degrees on the unit circle is located on radical 3/2, 1/2. This can be used for 150 degrees, 210 degrees, and 330 degrees. The only difference is that they are located on different quadrants and there will be negatives and positives.

2. The 45* Triangle
The 45* triangle has two sides that are the same length which are x and y the hypotenuse is r. To derive the unit circle from the triangle we have to get the hypotenuse to equal 1. In order to do this we divide every side by  x radical 2. Once we get one on the hypotenuse we can get r and figure out the points. For the angle of 45 degrees we plot radical two over two, radical two over two. This is where it will lie on the unit circle. This will also stand for 135, 225 and 315 degrees. The only differences are the quadrants the negatives.

3. The 60* Triangle

 
The 60 degree triangle is the same as the 30 degree triangle it has three different sides. In order to derive this triangle from the unit circle is to divide the hypotenuse to get one. This is the same as the 30 degree triangle because you divide by 2x. When you get your final answers you will be able to plot the points. The points for 60 degrees are 1/2, and radical 3/2. These rules also apply for 120,240, 300 degrees.

4.
This activity helps me derive the unit circle because the triangles reflect different points on the unit circle throughout all of the four quadrants. Each of these triangles can be found in all of these quadrants and are all the same the only exception is that there are negatives and positives and they are located in different quadrants too.

5.
The triangle in this activity lies in quadrant one both the x and y values are positive which means that it is in quadrant one.

Inquiry Activity Reflection:
1. The coolest thing I learned from this activity was how you can find the points on the unit circle by using the special triangles.
2. This activity will help me in this unit because it can help me memorize where different points are and where some points lie on different quadrants.
3.Something I have never realized before about the special right triangles and the unit circle are that both these are in relation to each other when the hypotenuse is equal to one

Tuesday, February 11, 2014

RWA #1: Unit M: Concept 6: Hyperbola Conic Section in Real Life

All there is you need to know about Hyperbolas
1. Mathematical Definition. A hyperbola is "a curve where the distances of any point from a fixed point 9 (the focus)and a fixed straight line (the directrix) are always in the same ratio."(mathisfun.com)

2. Describing the Conic Section Algebraically
http://www.mathwarehouse.com/hyperbola/graph-equation-of-a-hyperbola.php

http://www.mathwarehouse.com/hyperbola/graph-equation-of-a-hyperbola.php

These two pictures show the two formulas used for a hyperbola. The reason there are two different formulas is because the way each hyperbola branches out. This means that if the equation begins with x it will open up on the x- axis. You will also know that it is the horizontal transverse axis. If the equation begins with y it will open on the y-axis and you will also know that it is the vertical transverse axis. The different parts of this conic section on this axis are vertices, foci, and center. The conjugate axis includes co-vertices. The conjugate axis is the direction in which the hyperbola opens. Asymptotes are also very important they are shown as y=mx+b. The formula to find the asymptotes for a transeverse axis which is horizontal us y=k+ or - b/a (x-h). The formula to find the asymptotes for a transverse axis which is vertical is y=k + or - a/b (x-h).

Graphically:
http://www.sparknotes.com/math/precalc/conicsections/section1.rhtml

To find the center which is (h,k) they will be included in the formula so they are paired off with x and y. X is always with h and y is always with k. To find the vertices you use what you have already which is the center. For example if the hyperbola y is first then you find the center and then use the x from the center to find the vertices which is the number for a up and the number for a down. The same with the co-vertices except you go left and right. A and B are found when you take the square root of the denominators. If y is first a squared is underneath it and b squared is underneath x or vice versa. To find the asymptotes you use the formula given in the above paragraph.

Focus and Eccentricity
http://www.youtube.com/watch?v=S0Fd2Tg2v7M     (Khan Academy)

This video explained how an ellipse and a hyperbola are similar even with their foci. The eccentricity of a hyperbola should be 1 or above.The closer the eccentricity is to one the curves of the hyperbola will make it look sharper or more pointy. The farther away the eccentricity is to one it will make the curves of the hyperbola look straighter, which means it will look fatter. A smaller foci means a small width and a larger foci means a larger width.

3. Hyperbolas in real life

http://www.pleacher.com/mp/mlessons/calculus/apphyper.html


Hyperbolas can be found all over the real world for example a common household lamp can cast a shadow that is a hyperbola. Also in architecture like the Dulles Airport which is shaped like a hyperbola. The one i picked is a nuclear power plant's cooling tower. The reason that this is the standard shape for all cooling towers is because it needs to withstand high winds and be built with little material. When the cooling tower is in the shape of a hyperbola it is easier for the building to take the damage of high winds. This shape also is very inexpensive to build with steel beams and concrete.
As you can see the cooling tower looks like a cylinder. Well when you take a cylinder by each side and  push one side forward and one side back you will create a hyperbola. Hyperbolas can also be found with jets. As a jet breaks the sound barrier it releases a sonic boom. When the boom is released a cloud is formed and it looks like a cone, when it comes into contact with the ground then it becomes a hyperbola.

4. References
Vertical and Horizontal Transverse Axis of Hyperbola:
http://www.mathwarehouse.com/hyperbola/graph-equation-of-a-hyperbola.php
http://www.mathwarehouse.com/hyperbola/graph-equation-of-a-hyperbola.php

Different Conic Sections:
http://www.sparknotes.com/math/precalc/conicsections/section1.rhtml
Focus and Eccentricity: Khan Academy
http://www.youtube.com/watch?v=S0Fd2Tg2v7M

Hyperbola in Real World:
http://www.pleacher.com/mp/mlessons/calculus/apphyper.html