#$&*
course Mth 277
9/20/2011 @ 11:19 p.m.
If your solution to stated problem does not match the given solution, you should self-critique per instructions at
http://vhcc2.vhcc.edu/dsmith/geninfo/labrynth_created_fall_05/levl1_22/levl2_81/file3_259.htm
.
Your solution, attempt at solution. If you are unable to attempt a solution, give a phrase-by-phrase interpretation of the problem along with a statement of what you do or do not understand about it. This response should be given, based on the work you did in completing the assignment, before you look at the given solution.
At the end of this document, after the qa problems (which provide you with questions and solutions), there is a series of Questions, Problems and Exercises.
query_09_7
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Question: Identify the quadric surface 4y = (z^2)/4 - (x^2)/9.
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Your solution: If I put this in the form 0 = (-1/9)x^2 - 4y - (1/4)z^2, I am lead to believe that this is a 3D parabola since the general form of an ellipse and hyperbola require a y^2.
confidence rating #$&*:so
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Given Solution:
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Self-critique (if necessary):
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Self-critique rating:
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Question: Identify the quadric surface given by the equation 8z^2 = (1/8) + (x^2)/9 + (y^2). Describe the traces in planes parallel to the coordinate planes (and sketch the graph).
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Your solution: If I change the form on this equation, I get 0 = (1/9)x^2 + y^2 - 8z^2 + 1/8…which appears to be an ellipse. The ellipse is very narrow and goes a fair way down the y-axis. Its center is at the origin of the x-y-z axis.
confidence rating #$&*:i-confident
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Given Solution:
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Self-critique (if necessary):
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Self-critique rating:
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Question: Describe the quadric surface given by the equation ((x-3)^2)/2 - ((y-1)^2)/4 - (z^2-2)/9 = 4.
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Your solution: It is a hyperbola since, after expanding the equation, I get an equation with x^2, x, y^2, y, and z^2…which has an x and y which makes it a hyperbola instead of a parabola.
confidence rating #$&*:y
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Given Solution:
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Self-critique (if necessary):
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Self-critique rating:
@& In the plane x = 10, just to pick a usable number for x, this graph gives you an ellipse.
In some planes parallel to the yz axis you get ellipses, in some you get nothing. The size of the ellipse and whether there is an ellipse at all is determined by the value of x. How does the result change as x changes?
In any plane parallel to the yz axis the graph is a hyperbola, whose size depends on the fixed valud of y; and the same is so for any plane parallel to the xz axis, whose size depends on the fixed value of x.*@
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Question: Describe the curve intersection of the two quadric surfaces 4z = (y^2)/9 - (x^2)/16 and (x^2)/4 + 2(y^2) - 4(z^2)/3 = 1.
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Your solution: I do not have any idea how to do this problem, though I think the first equation is an ellipse and the second is a hyperbola.
confidence rating #$&*: at all.
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Given Solution:
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Self-critique (if necessary):
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Self-critique rating:
@& Start by finding the equation in each of the three coordinate planes. Identify the shape in each.
Then take slices parallel to the coordinate planes.*@
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Self-critique (if necessary):
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Self-critique (if necessary):
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#*&!
@& Check my notes and give this another shot. Hopefully today's class helped.*@