Pages

Wednesday, March 5, 2014

I/D #2: Unit O - Derive the SRTs

INQUIRY ACTIVITY SUMMARY

45-45-90
        
      To create a 45-45-90 triangle we must cut the square diagonally. Cutting the square diagonally will cut two of the 90 angles in half creating a 45 angle. To find the hypotenuse we must use the Pythagorean theorem. Since we know 'a' and 'b' we can plug that into the equation of a^2+b^2=c^2. Once we plug in 1 and 1 we get 2=c^2. We must get 'c' by itself and doing so by getting the square root of it canceling out the power of 2. What we do to one side we must do to the other and this gives us the 'square root of 2=c' and we now have the hypotenuse of 'square root of 2.'  We use 'n' on each side because the relationship between all 45-45-90 triangles would be the same. 



30-60-90
   
        To create the special right triangle of 30-60-90 we must cut an equilateral triangle right down the center. We do this to create two triangles and it divides the top 60 angle in half and creates a 30 angle in each triangle. Doing this also makes the 90 angles at the bottom of the triangle. Put it all together and we have the 30-60-90 triangle. Since the bottom length of the triangle was 1 cutting the triangle down the middle makes it 1/2 in both triangles. To get the height of the triangle we must use the Pythagorean theorem. a=1/2 and c=1 leaving us to find 'b', the height. Since a=1/2 we will multiply all sides by 2 to get rid of the 1/2. The equation will now be 1^2+b^2=2^2. After we solve for 'b' we will get the 'square root of 3' as the height. We again use 'n' to show the relation between all 30-60-90 triangles and how they each will have the same variables such as 2n,n, and n|3. 


 INQUIRY ACTIVITY REFLECTION
       Something I never noticed before about special right triangles is that every special right triangle will have the same relations no matter what the lengths of the triangle are.

Being able to derive these patterns myself aids in my learning because now I completely understand where the variables come from and it makes more sense of what I am doing when I am solving for problems that involve this.

Monday, February 10, 2014

RWA1: Unit M Concepts 4-6 - Conic Sections in real life.



http://www.youtube.com/watch?v=lvAYFUIEpFI
http://www.mathsisfun.com/geometry/ellipse.html

1. An ellipse is the set of all points on a plane whose distance from two points add up to be a constant

2. The equation algebraically is (x-h)^2/a^2+(y-k)^2/b^2=1
     An ellipse is almost like a smashed circle. (as shown above)
     To find the standard form we must use the center point of the ellipse and plug it into the equation.(x,y)=(h,k). If the ellipse is skinny a^2 goes under y and if its fat a^2 goes under x. the major axis is the longest diameter of the ellipse and the minor axis is the shortest. To find a you would find the number from one of the vertices to the center of the ellipse. To find b you would find the distance from one of the covertices to the center. To find c we would have to use a^2-b^2=c^2. To find the eccentricity we put c over a and it should be less than 1. If you place the foci farther away from the center the wider the ellipse will get. 

3. Conic sections are used everyday in the real world. They may not seem huge but they make an important difference. One example is with tanks that carry heating oil or gasoline. The tanks are never circular but rather elliptical. "This gives them a high capacity, but with a lower center-of-gravity, so that they are more stable when being transported." (http://mathforum.org/library/drmath/view/62576.html) If the tank was a circle then its height would be greater and it wouldn't fit under bridges. Without an elliptical tank things like oil and gasoline would be much harder to transport.
     These conic sections also get things going such as bicycles. The gear that connects to the pedal crank is basically an elliptical shape. "Here the difference between the major and minor
  axes of the ellipse is used to account for differences in the speed and force applied"(http://mathforum.org/library/drmath/view/62576.html)
With this elliptical shape your legs are able to push and pull more effectively. Conic sections are used everyday in the real world with things that are the least noticeable yet make the biggest differences. A world without conic sections would be difficult.
 
4. References:
. http://mathforum.org/library/drmath/view/62576.html
. http://www.mathsisfun.com/geometry/ellipse.html
. http://www.youtube.com/watch?v=lvAYFUIEpFI
. http://www.mathopenref.com/ellipseaxes.html
. http://www.mathopenref.com/ellipsefoci.html 

Saturday, November 30, 2013

Fibonacci Haiku: Food

http://www.bubblews.com/assets/images/news/291197009_1384697316.jpg

Tasty
Delicious
Mouth Watering
Carefully Prepared Deliciousness
Food, From around the World
Deserves to be in my big fat stomach