Recent Changes

Tuesday, January 8

  1. page home edited ... (current assignment) Chapter 12 Project ... for details. Here is a summary of the deadlin…
    ...
    (current assignment)
    Chapter 12 Project
    ...
    for details. Here is a summary of the deadlines:
    Date
    Points Possible
    What is due?
    Did I do it? (Check off)
    Monday 4/30
    1
    Topic chosen, write topic sentence
    Create wiki page
    Tuesday 5/1
    8
    Description paragraph(s)
    Wednesday 5/2
    5
    Vertex details
    Tuesday 5/8
    12 (4 for each eqn.)
    Equations: vertex, standard, factored forms
    Friday 5/11
    10
    Graph and description of graph
    Friday 5/11
    3
    y-intercept details
    Tuesday 5/15
    3
    Discriminant details
    Wednesday 5/16
    5
    x-intercepts details
    Wednesday 5/23
    3
    Problem written and solved
    Friday 5/25
    50
    FINAL PROJECT
    Presentation
    Bonus details if you like (worth up to 4 points each)

    (first wiki assignment)
    Who, what, when, where, and why are Parabolas?
    (view changes)
    9:36 am

Tuesday, May 29

Monday, May 28

  1. page A. Murray Mackay Bridge edited ... Y-Intercept: There is only one y-intercept for the parabola and that is the point (0,96). Dis…
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    Y-Intercept: There is only one y-intercept for the parabola and that is the point (0,96).
    Discriminant: The discriminant is -0.016
    X-Intercept: ThereThere are no
    Problem: A child is flying a kite on the A. Murray MacKay Bridge. The child is 2 meters tall, not including his kite. The kite, including the kite top and the string, is 25.5 meters. How long will the boy get before his flag touches the bridges parabola. The answer is 100 meters.
    (view changes)
    7:26 pm
  2. page A. Murray Mackay Bridge edited ... A. Murray MacKay Bridge For my parabola I choose the A. Murray MacKay Bridge. The A. Murray M…
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    A. Murray MacKay Bridge
    For my parabola I choose the A. Murray MacKay Bridge. The A. Murray MacKay connecting Halifax and Dartmouth was built in 1970 when it became the first suspension bridge in North America to use orthotropic plate deck in its construction. After this work it is a bridge that can accommodate movements as high as 3.2 metres, which mean it is enabled to survive an earthquake. There is a large history around the site of this bridge, which is at the Narrows, a narrowing at the inner end of Halifax Harbor where it opens into the Bedford Basin. The Bedford Basin was where many fleets of ships were formed to carry troops and supplies to Europe during the First and Second World Wars. The Narrows was the site of the Halifax Explosion, where the French munitions ship Mont Blanc collided with another ship, drifted to the Halifax side of the Narrows, and exploded at 9:05 AM on December 6, 1917 completely destroying over 1600 homes and killing almost 2000 people in what was the largest man-made explosion in history before the atomic bomb was dropped on Hiroshima in 1945. A large area in the north end of the city was flattened in the blast and many thousands were left homeless.
    ...
    x in (x,y0(x,y) of the
    ...
    in the vertex because the lowest point in the vertex, the lowest y point of the parabola, or the bridge, is 2 meters away from the road, or the x axis, which by the way was my estimate I could not find the exact distance from the ground.
    Equations: The equation for the parabola in...
    Standard form: y=0.002x^2-0.852x+92.738
    Vertex form: y-2=0.002(x-213)^2
    Factored form: It cannot be put in factored form because the parabola has no x-intercepts.
    Picture of Graph:
    {Screen_Shot_2012-05-28_at_9.12.14_PM.png}
    Y-Intercept: There is only one y-intercept for the parabola and that is the point (0,96).
    Discriminant: The discriminant is -0.016
    X-Intercept: There are no x-intercepts because the parabola never crosses or touches the x-axis.
    Problem: A child is flying a kite on the A. Murray MacKay Bridge. The child is 2 meters tall, not including his kite. The kite, including the kite top and the string, is 25.5 meters. How long will the boy get before his flag touches the bridges parabola. The answer is 100 meters.

    (view changes)
    7:24 pm
  3. page Parabolic Reflector edited ... {PHYSICS-OPTICS-parabolic-light-tilted.jpg} {lighthouses.jpg} I traced my original graph o…
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    {PHYSICS-OPTICS-parabolic-light-tilted.jpg} {lighthouses.jpg}
    I traced my original graph on graph paper and went on Exel, then I graphed the known points which were: (9,7), (-9,7), and (0,0). The equation I got was y=.0864x^2 in standard form. Here is my graph: {screenshot-20120524-153835.png}
    ...
    x-intercept,and vertex equalsall equaled zero but
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    anything else. An easy way to find the y-intercept or x-intercept without looking at the graph is to find is to find it in factored form equation. An easy way of finding the vertex would be looking at the vertex form equation. I decided
    ...
    For factored iI got y=.0864(x-0)^2,y=.0864(x-0)(x-0), and for
    ...
    I got y=.0864(x-0)(x-0).y=.0864(x-0)^2
    .

    For the quadratic formula, I got x=-1 +- sqrt (1-4(.0864)(1)) over 2(1). Then I knew that my discriminant was .6544.
    Problem:
    (view changes)
    7:24 pm
  4. page A. Murray Mackay Bridge edited Sloan Gormley A. Murray MacKay Bridge For my parabola I choose the A. Murray MacKay Bridge. The …
    Sloan Gormley
    A. Murray MacKay Bridge
    For my parabola I choose the A. Murray MacKay Bridge. The A. Murray MacKay connecting Halifax and Dartmouth was built in 1970 when it became the first suspension bridge in North America to use orthotropic plate deck in its construction. After this work it is a bridge that can accommodate movements as high as 3.2 metres, which mean it is enabled to survive an earthquake. There is a large history around the site of this bridge, which is at the Narrows, a narrowing at the inner end of Halifax Harbor where it opens into the Bedford Basin. The Bedford Basin was where many fleets of ships were formed to carry troops and supplies to Europe during the First and Second World Wars. The Narrows was the site of the Halifax Explosion, where the French munitions ship Mont Blanc collided with another ship, drifted to the Halifax side of the Narrows, and exploded at 9:05 AM on December 6, 1917 completely destroying over 1600 homes and killing almost 2000 people in what was the largest man-made explosion in history before the atomic bomb was dropped on Hiroshima in 1945. A large area in the north end of the city was flattened in the blast and many thousands were left homeless.
    Vertex: The vertex is (213,2) because half of the parabola, the middle of the bridge from pole to pole, is 213 meters, which is the x in (x,y0 of the vertex. 2 is the y in the

    (view changes)
    6:52 pm

Thursday, May 24

  1. page Parabolic Reflector edited ... {PHYSICS-OPTICS-parabolic-light-tilted.jpg} {lighthouses.jpg} I traced my original graph o…
    ...
    {PHYSICS-OPTICS-parabolic-light-tilted.jpg} {lighthouses.jpg}
    I traced my original graph on graph paper and went on Exel, then I graphed the known points which were: (9,7), (-9,7), and (0,0). The equation I got was y=.0864x^2 in standard form. Here is my graph: {screenshot-20120524-153835.png}
    ...
    I got y=.0864(x-0)(x-0)y=.0864(x-0)(x-0).
    For the quadratic formula, I got x=-1 +- sqrt (1-4(.0864)(1)) over 2(1). Then I knew that my discriminant was .6544.
    Problem:
    When a headlight is 4 inches long, how wide is the light that is reflected off of it?
    4=.0864x^2
    0=.0864x^2 -4
    x= -1 +- sqrt (1^2 - 4(.0864)(-4)) over 2(.0864)
    x= 3.14536916 and -14.7193432

    (view changes)
    2:50 pm
  2. page Parabolic Reflector edited ... {parabolic_reflector.png} Parabolic reflectors started when the mathematician Diocles descr…
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    {parabolic_reflector.png}
    Parabolic reflectors started when the mathematician Diocles described them in his book On Burning Mirrors and proved that they focus a parallel beam to a point. Archimedes then later studied them and it is rumoured that he then used them to set a Roman fleet alight. Newton also used them for his telescope and they were also used in lighthouses until the late 19th century.
    {PHYSICS-OPTICS-parabolic-light-tilted.jpg} {lighthouses.jpg}
    I traced my original graph on graph paper and went on Exel, then I graphed the known points which were: (9,7), (-9,7), and (0,0). The equation I got was y=.0864x^2 in standard form. Here is my graph: {screenshot-20120524-153835.png}
    I found it strange that my parabola's y-intercept, x-intercept,and vertex equals zero but I found out that because my parabola is used for things like car headlights, that it couldn't be anything else. I decided to convert my equation to factored and vertex form as well. For factored i got y=.0864(x-0)^2, and for vertex I got y=.0864(x-0)(x-0)
    (view changes)
    2:16 pm
  3. file lighthouses.jpg uploaded
    2:16 pm

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