Assignment - 22

course Mth163

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.

022. `query 22

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Question: `qExplain why the function y = x^-p has a vertical asymptote at x = 0.

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Your solution:

Because of the neg. exponential function y = x^-p will be rewritten as y = 1/x^p

Which makes its graph vertical asymptote because it will come closer and closer to the x axis.

Confidence rating: positive

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Given Solution:

`a** x^-p = 1 / x^p.

As x gets closer to 0, x^p gets closer to 0. Dividing 1 by a number which gets closer and closer to 0 gives us a result

with larger and larger magnitude.

There is no limit to how close x can get to 0, so there is no limit to how many times x^p can divide into 1.

This results in y = x^p values that approach infinite distance from the x axis. The graph therefore approaches a vertical

limit. **

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Self-critique (if necessary):

As x gets closer to 0 so does 1/x^p, approaching infinity distance from the x axis.

Self-critique rating:

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Question: `qExplain why the function y = (x-h)^-p has a vertical asymptote at x = h.

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Your solution:

Again you are given a neg. power giving you y = (x-h)^-p as y = 1/(x-h)^p, also given that there is no limit on how many times(x-h)^p can divide into 1, we have an y = 1/(x-h)^p approaching infinity distance from the x axis.

Confidence rating: mostly

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Given Solution:

`a** (x-h)^-p = 1 / (x-h)^p.

As x gets closer to h, (x-h)^p gets closer to 0. Dividing 1 by a number which gets closer and closer to 0 gives us a result

with larger and larger magnitude.

There is no limit to how close x can get to h, so there is no limit to how many times (x-h)^p can divide into 1.

This results in y = (x-h)^p values that approach infinite distance from the x axis as x approaches h. The graph therefore

approaches a vertical limit.

This can also be seen as a horizontal shift of the y = x^-p function. Replacing x by x - h shifts the graph h units in the x

direction, so the asymptote at x = 0 shifts to x = h. **

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Self-critique (if necessary):

as x gets closer to h, (x-h)^p gets closer to 0

It therefore approaches a vertical limit

Remember h is a representation of a horizontal shift, shifting the x horizontally.

Self-critique rating:

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Question: `qExplain why the function y = (x-h)^-p is identical to that of x^-p except for the shift of h units in the

x direction.

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Your solution:

Looking above I see that when x = 0 as y = (x-h)^p = 0 when x = h

Confidence rating: mostly

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Given Solution:

`aSTUDENT ANSWER: You end up with the exact same y values but at the different position of x changed by the h

value.

INSTRUCTOR COMMENT: Good start. More specifically the x value at which a given y value occurs is shifted h

units, so that for example y = x^p is zero when x = 0, but y = (x - h)^p is zero when x = h.

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Self-critique (if necessary):

x value at which a given y value occurs is shifted h units

Self-critique rating:

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Question: `qGive your table (increment .4) showing how the y = x^-3 function can be transformed first into y =

(x - .4) ^ -3, then into y = -2 (x - .4) ^ -3, and finally into y = -2 (x - .4) ^ -3 + .6.

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Your solution:

using x values from -2 to 2

x (x-.4)-3 -2(x - .4)^-3 -2(x-4)^-3 + .6 y = x^-3

1/(x-4)^3 -2 * 1/(x-.4)^3 -2 * 1/(x-.4)^3 + .6 y= 1/x^3

-2 -.072337963 1.446759259 .7446759259 -.125

-1 -.3644314869 .7288629738 1.328862974 -1

0 -15.625 31.25 31.85 undefined

1 4.62962963 -9.259259259 -8.659259259 1

2 .244140625 -.48828125 .11171875 .125

Confidence rating: positive

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Given Solution:

`atable has each transformation across the top with beginning x value in first column then each change to x to get the y

values in resulting columns

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Your solution:

ok

Confidence rating:

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Given Solution:

`a** The table is as follows (note that column headings might not line up correctly with the columns):

x y=x^-3 y= (x-.4)^-3 y= -2(x-.4)^-3 y= -2(x-.4)^-3 +.6

0.8 1.953 15.625 31.25 31.85

0.4 15.625 div/0 0 0.6

0 div/0 -15.625 -31.25 -30.65

-0.4 -15.625 -1.953 3.906 4.506

-0.8 -1.953 -0.579 1.158 1.758

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Self-critique (if necessary):

ok

Self-critique rating:

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Question: `qExplain how your table demonstrates this transformation and describe the graph that depicts the

transformation.

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Your solution:

the graph of y = (x-.4)^-3 shifts the y = x^-3 to the right

the graph of y = -2(x-.4)^-3 vertically stretches y = (x-.4)^-3 a -2

the graph of y = -2(x-.4)^-3 + .6 vertically shifts y = -2(x-.4)^-3 up .6 units in the positive direction

Confidence rating: mostly

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Given Solution:

`ay = x^-3 transforms into y = (x - .4)^-3, shifting the basic points .4 unit to the right. The vertical asymptote at the y axis

(x = 0) shifts to the vertical line x = .4. The x axis is a horizontal asymptote.

y = -2 (x - .4)^-3 vertically stretches the graph by factor -2, moving every point twice as far from the x axis and also to

the opposite side of the x axis. This leaves the vertical line x = .4 as a vertical asymptote. The x axis remains a horizontal

asymptote.

y = -2 ( x - .4)^-3 + 6 vertically shifts the graph +6 units. This has the effect of maintaining the shape of the graph but

raising the horizontal asymptote to x = 6.

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Self-critique (if necessary):

The first graph is a horizontal asymptote of the x axis

The second graph is stretched -2 every point from x axis and to the opposite side of the graph

The last graph did not change shape of graph.

Self-critique rating:

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Question: `qDescribe your graphs of y = x ^ .5 and y = 3 x^.5. Describe how your graph depicts the ratios of y

values between the two functions.

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Your solution:

Graphing this on my calculator the graph of y = x^.5, it increases at a decreasing rate, showing a slight curve as it decreases.

The graph of y = 3x^.5 is also increasing at a decreasing rate showing a slight curve as it is decreasing but it is stretched 3 units up from the y = x^.5 graph

Confidence rating: positive

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Given Solution:

`a*&*& This is a power function y = x^p with p = .5.

The basic points of y = x^.5 are (0, 0), (.5, .707), (1, 1), (2, 1.414). Attempting to find a basic point at x = -1 we find

that -1^-.5 is not a real number, leading us to the conclusion that y = x^.5 is not defined for negative values of x. The

graph therefore begins at the origin and increases at a decreasing rate. However since we can make x^.5 as large as we

wish by making x sufficiently large, there is no horizontal asymptote.

y = 3 x^.5 vertically stretches the graph of y = x^.5 by factor 3, giving us basic ponits (0, 0), (.5, 2.12), (1, 3) and (2,

4.242). This graph is also increasing at a decreasing rate, staying 3 times as far from the x axis as the graph of the original

y = x^.5.

problem 6.

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Self-critique (if necessary):

ok with x = 0, .5, 1, 2 we have y values = 0, .707, 1, 1.414 for the first graph, a neg. exponent shows y isn’t a real # showing the graph to lie in the positive and also isn’t a asymptote

using the same x values for the second graph, y = 0, 2,12, 3, 4.242

Self-critique rating:

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Question: `qExplain why the graph of A f(x-h) + k is different than the graph of A [ f(x-h) + k ], and describe

the difference.

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Your solution:

The order of operation is the changes between the original A F(x-h) + K and A[f(x-h) + K]:

the second graph is the same except the vertical stretch of A will be multiplied by the vertical shift, K, along with the (x-h)

Confidence rating: positive

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Given Solution:

`a** The first graph is obtained from y = f(x) by first vertically stretching by factor A, then horizontall shifting h units and

finally vertically shifting k units.

The graph of A [f(x-h) + k] is obtained by first doing what is in brackets, horizontally shifting h units then vertically shifting

k units before doing the vertical stretch by factor A. Thus the vertical stretch applies to the vertical shift in addition to the

values of the function. This results in different y coordinates and a typically a very different graph.

Query Add comments on any surprises or insights you experienced as a result of this assignment.

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Self-critique (if necessary):

ok

Self-critique rating:

"

Good answers and self-critiques.

&#Let me know if you have questions. &#