HiSET: Math : Translations

Study concepts, example questions & explanations for HiSET: Math

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Example Questions

Example Question #1 : Understand Transformations In The Plane

 

Translation

The graph on the left shows an object in the Cartesian plane. A transformation is performed on it, resulting in the graph on the right. 

Which of the following transformations best fits the graphs?

Possible Answers:

Dilation

Reflection in the y-axis

Translation

Reflection in the x-axis

Rotation about the origin

Correct answer:

Translation

Explanation:

A dilation is the stretching or shrinking of a figure.

A rotation is the turning of a a figure about a point. 

A reflection is the flipping of a figure across a line.

A translation is is the sliding of a figure in a direction. 

With a translation, the image is not only congruent to its original size and shape, but its orientation remains the same. A translation fits this figure best because the shape seems to move upward and rightward without changing size, shape, or orientation.

Example Question #2 : Translations

Translate the graph of the equation

\(\displaystyle 4x- 7y = 15\)

left four units and down six units. Give the equation of the image.

Possible Answers:

\(\displaystyle 4x- 7y = 45\)

\(\displaystyle 4x- 7y = 25\)

\(\displaystyle 4 x- 7 y = −43\)

\(\displaystyle 4 x- 7 y = 73\)

\(\displaystyle 4 x- 7 y = 41\)

Correct answer:

\(\displaystyle 4 x- 7 y = 41\)

Explanation:

If the graph of an equation is translated to the right \(\displaystyle h\) units, and upward \(\displaystyle k\) units, the equation of the image can be found by replacing \(\displaystyle x\) with \(\displaystyle x-h\) and \(\displaystyle y\) with \(\displaystyle y-k\) in the equation of the original graph. 

Since we are moving the graph of the equation

\(\displaystyle 4x- 7y = 15\)

left four units and down six units, we set \(\displaystyle h = -4\) and \(\displaystyle k = -6\); we can replace \(\displaystyle x\) with \(\displaystyle x - (-4)\), or \(\displaystyle x+ 4\), and \(\displaystyle y\) with \(\displaystyle y - (-6 )\), or \(\displaystyle y + 6\). The equation of the image can be written as

\(\displaystyle 4 (x+ 4)- 7 (y+6) = 15\)

Simplify by distributing:

\(\displaystyle 4 x+4( 4)- 7 y-7(6) = 15\)

\(\displaystyle 4 x+16- 7 y-42 = 15\)

Collect like terms:

\(\displaystyle 4 x- 7 y +16-42 = 15\)

\(\displaystyle 4 x- 7 y -26 = 15\)

Add 26 to both sides:

\(\displaystyle 4 x- 7 y -26 +26 = 15+26\)

\(\displaystyle 4 x- 7 y = 41\),

the correct choice.

Example Question #6 : Understand Transformations In The Plane

Translate the graph of the equation

\(\displaystyle x^{2}+ y^{2}= 100\)

right two units and up five units. Give the equation of the image.

Possible Answers:

None of the other choices gives the correct response.

\(\displaystyle x^{2}+ 4x + y^{2}+10y-71=0\)

\(\displaystyle x^{2}- 4x + y^{2}-10y-71=0\)

\(\displaystyle x^{2}+ 2x + y^{2}+5y-71=0\)

\(\displaystyle x^{2}- 2x + y^{2}-5y-71=0\)

Correct answer:

\(\displaystyle x^{2}- 4x + y^{2}-10y-71=0\)

Explanation:

If the graph of an equation is translated to the right \(\displaystyle h\) units, and upward \(\displaystyle k\) units, the equation of the image can be found by replacing \(\displaystyle x\) with \(\displaystyle x-h\) and \(\displaystyle y\) with \(\displaystyle y-k\) in the equation of the original graph. 

Since we are moving the graph of the equation

\(\displaystyle x^{2}+ y^{2}= 100\)

right two units and up five units, we set \(\displaystyle h = 2\) and \(\displaystyle k = 5\); we can therefore replace \(\displaystyle x\) with \(\displaystyle x- 2\) and \(\displaystyle y\) with \(\displaystyle y - 5\). The equation of the image can be written as 

\(\displaystyle (x-2)^{2}+( y-5)^{2}= 100\)

This can be rewritten by applying the binomial square pattern as follows:

\(\displaystyle x^{2}- 2 (x) (2)+ 2^{2}+ y^{2}- 2 (5)(x)+ 5^{2} = 100\)

\(\displaystyle x^{2}- 4x+4+ y^{2}-10y+2 5 = 100\)

Collect like terms; the equation becomes

\(\displaystyle x^{2}- 4x + y^{2}-10y+29 = 100\)

Subtract 100 from both sides:

\(\displaystyle x^{2}- 4x + y^{2}-10y+29- 100 = 100 - 100\)

\(\displaystyle x^{2}- 4x + y^{2}-10y-71=0\)

Example Question #1 : Translations

Translate the graph of the equation

\(\displaystyle y = x^{2}+ 5x - 7\)

right four units and down two units. Give the equation of the image.

Possible Answers:

\(\displaystyle y= x^{2} -3x-9\)

\(\displaystyle y = x^{2}+ 13x + 27\)

\(\displaystyle y= x^{2} -3x-13\)

\(\displaystyle y = x^{2}+ 13x -9\)

\(\displaystyle y = x^{2}+ 13x + 29\)

Correct answer:

\(\displaystyle y= x^{2} -3x-13\)

Explanation:

If the graph of an equation is translated to the right \(\displaystyle h\) units, and upward \(\displaystyle k\) units, the equation of the image can be found by replacing \(\displaystyle x\) with \(\displaystyle x-h\) and \(\displaystyle y\) with \(\displaystyle y-k\) in the equation of the original graph. 

Since we are moving the graph of the equation

\(\displaystyle y = x^{2}+ 5x - 7\)

right four units and down two units, we set \(\displaystyle h = 4\) and \(\displaystyle k = -2\); we can therefore replace \(\displaystyle x\) with \(\displaystyle x- 4\), and \(\displaystyle y\) with \(\displaystyle y - (-2)\), or \(\displaystyle y+ 2\). The equation of the image can be written as

\(\displaystyle y+2 = (x-4)^{2}+ 5(x-4) - 7\)

The expression at right can be simplified. First, use the distributive property on the middle expression:

\(\displaystyle y+2 = (x-4)^{2}+ 5x-5 (4) - 7\)

\(\displaystyle y+2 = (x-4)^{2}+ 5x-20 - 7\)

Now, simplify the first expression by using the binomial square pattern:

\(\displaystyle y+2 = x^{2} -2 (x)(4) +4^{2}+ 5x-20 - 7\)

\(\displaystyle y+2 = x^{2} -8x+16+ 5x-20 - 7\)

Collect like terms on the right:

\(\displaystyle y+2 = x^{2} -8x+ 5x+16 -20 - 7\)

\(\displaystyle y+2 = x^{2} -3x-11\)

Subtract 2 from both sides:

\(\displaystyle y+2 -2= x^{2} -3x-11-2\)

\(\displaystyle y= x^{2} -3x-13\),

the equation of the image.

Example Question #51 : Measurement And Geometry

Translate the graph of the equation

\(\displaystyle y = | 3x - 8 |\)

left three units and down five units. Give the equation of the image.

Possible Answers:

\(\displaystyle y = | 3x+1 | - 5\)

\(\displaystyle y = | 3x-17 | - 5\)

\(\displaystyle y = | 3x+1 | +5\)

\(\displaystyle y = | 3x-17 | + 5\)

None of the other choices gives the correct response.

Correct answer:

\(\displaystyle y = | 3x+1 | - 5\)

Explanation:

If the graph of an equation is translated to the right \(\displaystyle h\) units, and upward \(\displaystyle k\) units, the equation of the image can be found by replacing \(\displaystyle x\) with \(\displaystyle x-h\) and \(\displaystyle y\) with \(\displaystyle y-k\) in the equation of the original graph. 

Since we are moving the graph of the equation

\(\displaystyle y = | 3x - 8 |\)

left three units and down five units, we set \(\displaystyle h = -3\) and \(\displaystyle k = -5\); we can therefore replace \(\displaystyle x\) with \(\displaystyle x- (-3)\), or \(\displaystyle x +3\), and \(\displaystyle y\) with \(\displaystyle y - (-5)\), or \(\displaystyle y+ 5\). The equation of the image can be written as

\(\displaystyle y+5 = | 3(x+3) - 8 |\)

We can simplify the expression on the right by distributing:

\(\displaystyle y+5 = | 3x+3 \cdot 3 - 8 |\)

\(\displaystyle y+5 = | 3x+9- 8 |\)

Collect like terms:

\(\displaystyle y+5 = | 3x+1 |\)

Subtract 5 from both sides:

\(\displaystyle y+5 -5 = | 3x+1 | - 5\)

\(\displaystyle y = | 3x+1 | - 5\),

the correct equation of the image.

Example Question #1 : Translations

On the coordinate plane, let \(\displaystyle A\) and \(\displaystyle B\) be located at \(\displaystyle (3, 9)\) and \(\displaystyle (9, -5)\), respectively. Let \(\displaystyle M\) be the midpoint of \(\displaystyle \overline{AB}\) and let \(\displaystyle N\) be the midpoint of \(\displaystyle \overline{AM}\). On the segment, perform the translation \(\displaystyle N \rightarrow B\). Where is the image of \(\displaystyle M\) located?

Possible Answers:

\(\displaystyle (6, 2)\)

\(\displaystyle \left (\frac{21}{2},-\frac{17}{2} \right )\)

\(\displaystyle \left ( \frac{25}{2}, \frac{3}{2} \right )\)

\(\displaystyle \left ( \frac{15}{2}, -\frac{3}{2} \right )\)

\(\displaystyle (12, -12)\)

Correct answer:

\(\displaystyle \left (\frac{21}{2},-\frac{17}{2} \right )\)

Explanation:

The midpoint of a segment with endpoints at \(\displaystyle (x_{1}, y_{1})\) and \(\displaystyle (x_{2}, y_{2})\) is located at

\(\displaystyle \left ( \frac{x_{1}+x_{2}}{2}, \frac{y_{1}+y_{2}}{2} \right )\)

Substitute the coordinates of \(\displaystyle A\) and \(\displaystyle B\) in this formula to find that midpoint \(\displaystyle M\) of \(\displaystyle \overline{AB}\) is located at

\(\displaystyle \left ( \frac{3+9}{2}, \frac{9+(-5)}{2} \right )\), or \(\displaystyle (6, 2)\).

Substitute the coordinates of \(\displaystyle A\) and \(\displaystyle M\) to find that midpoint \(\displaystyle N\) of \(\displaystyle \overline{AM}\) is located at

\(\displaystyle \left ( \frac{3+6}{2}, \frac{9+2}{2} \right )\), or \(\displaystyle \left ( \frac{9}{2}, \frac{11}{2} \right )\).

To perform the translation \(\displaystyle N \rightarrow B\), or, equivalently,

\(\displaystyle \left ( \frac{9}{2}, \frac{11}{2} \right ) \rightarrow (9, -5)\),

on a point, it is necessary to add

\(\displaystyle 9 - \frac{9}{2} = \frac{18}{2} - \frac{9}{2} = \frac{9}{2}\)

to its \(\displaystyle x\)-coordinate, and

\(\displaystyle -5 - \frac{11}{2} = - \frac{10}{2} - \frac{11}{2} = - \frac{21}{2}\)

to its \(\displaystyle y\)-coordinate.

Therefore, the \(\displaystyle x\)-coordinate of the image of \(\displaystyle M\) under this translation is

\(\displaystyle 6+ \frac{9}{2} = \frac{12}{2}+ \frac{9}{2} = \frac{21}{2}\);

its \(\displaystyle y\)-coordinate is

\(\displaystyle 2 + \left (- \frac{21}{2} \right ) = \frac{4}{2}- \frac{21}{2}=-\frac{17}{2}\)

The image of \(\displaystyle M\) is located at \(\displaystyle \left (\frac{21}{2},-\frac{17}{2} \right )\).

 

 

Example Question #2 : Translations

Consider regular Hexagon \(\displaystyle ABCDEF\).

On this hexagon, perform the translation \(\displaystyle A\rightarrow B\). Then reflect the hexagon about \(\displaystyle \overleftrightarrow{BD}\). Let \(\displaystyle A'\) be the image of \(\displaystyle A\) under these transformations, and so forth.

Which point on Hexagon \(\displaystyle ABCDEF\) is the image of \(\displaystyle F\) under these transformations?

Possible Answers:

\(\displaystyle D\)

\(\displaystyle E\)

\(\displaystyle F\)

\(\displaystyle C\)

\(\displaystyle A\)

Correct answer:

\(\displaystyle C\)

Explanation:

The translation \(\displaystyle A\rightarrow B\) on a figure is the translation that shifts a figure so that the image of \(\displaystyle A\), which we will call \(\displaystyle A''\), coincides with \(\displaystyle B\). All other points shift the same distance in the same direction. Below shows the image of the given hexagon under this translation, with the image of \(\displaystyle F\) marked as \(\displaystyle F''\):

1

If the image is reflected about \(\displaystyle \overleftrightarrow{BD}\), the new image is the original hexagon. Calling \(\displaystyle F'\) the image of \(\displaystyle F''\) under this reflection, we get the following:

1

 

\(\displaystyle F'\), the image of \(\displaystyle F\) under these two transformations, coincides with \(\displaystyle C\).

Example Question #51 : Measurement And Geometry

Consider regular Hexagon \(\displaystyle ABCDEF\).

On this hexagon, perform the translation \(\displaystyle A\rightarrow B\). Then perform a \(\displaystyle 120^{\circ }\) rotation on the image with center at \(\displaystyle B\). Let \(\displaystyle A'\) be the image of \(\displaystyle A\) under these transformations, and so forth.

Which of the following correctly shows Hexagon \(\displaystyle A'B'C'D'E'F'\) relative to Hexagon \(\displaystyle ABCDEF\)?

Possible Answers:

Hexagons

Hexagons

Hexagons

Hexagons

Hexagons

Correct answer:

Hexagons

Explanation:

The translation \(\displaystyle A\rightarrow B\) on a figure is the translation that shifts a figure so that the image of \(\displaystyle A\), which we will call \(\displaystyle A''\), coincides with \(\displaystyle B\). All other points shift the same distance in the same direction. Below shows the image of the given hexagon under this translation:

1

If this new hexagon is rotated clockwise \(\displaystyle 120 ^{\circ }\) - one third of a turn - about \(\displaystyle B\), and call \(\displaystyle A '\) the image of \(\displaystyle A''\), and so forth, the result is as follows:

1

Removing the intermediate markings, we see that the correct response is 

Hexagons

Example Question #51 : Measurement And Geometry

Consider regular Hexagon \(\displaystyle ABCDEF\).

On this hexagon, perform the translation \(\displaystyle F\rightarrow C\). Then perform a \(\displaystyle 180^{\circ }\) rotation on the image with center at \(\displaystyle C\)

Let \(\displaystyle A'\) be the image of \(\displaystyle A\) under these transformations, \(\displaystyle B'\) be the image of \(\displaystyle B\), and so forth. Under these images, which point on the original hexagon does \(\displaystyle D'\) fall?

Possible Answers:

\(\displaystyle F\)

\(\displaystyle E\)

\(\displaystyle B\)

\(\displaystyle C\)

\(\displaystyle A\)

Correct answer:

\(\displaystyle A\)

Explanation:

The translation \(\displaystyle F\rightarrow C\) on a figure is the translation that shifts a figure so that the image of \(\displaystyle F\) coincides with \(\displaystyle C\). All other points shift the same distance in the same direction. Below shows the image of the given hexagon under this translation, with \(\displaystyle D''\) the image of \(\displaystyle D\):

1

If this new hexagon is rotated \(\displaystyle 180 ^{\circ }\) - one half of a turn - about \(\displaystyle C\) - the image is the original hexagon, but the vertices can be relabeled. Letting \(\displaystyle D'\) be the image of \(\displaystyle D''\) under this rotation, and so forth:

1

\(\displaystyle D'\) coincides with \(\displaystyle A\) in the original hexagon, making \(\displaystyle A\) the correct response.

Example Question #54 : Measurement And Geometry

On the coordinate plane, let \(\displaystyle O\), \(\displaystyle A\), and \(\displaystyle B\) be located at the origin, \(\displaystyle (8, 0)\), and \(\displaystyle (6, 4)\). Construct the median of \(\displaystyle \bigtriangleup OAB\) from \(\displaystyle A\) and let the foot of the median be \(\displaystyle M\). On the triangle, perform the translation \(\displaystyle A \rightarrow M\). Where is the image of \(\displaystyle B\)?

Possible Answers:

\(\displaystyle (-3, -2)\)

\(\displaystyle (9,6)\)

\(\displaystyle (10,4)\)

\(\displaystyle (1,6)\)

\(\displaystyle (11,2)\)

Correct answer:

\(\displaystyle (1,6)\)

Explanation:

By definition, a median of a triangle has as its endpoints one vertex and the midpoint of the opposite side. Therefore, the endpoints of the median from \(\displaystyle A\) are \(\displaystyle A\) itself, which is at \(\displaystyle (8, 0)\), and \(\displaystyle M\), which itself is the midpoint of the side with origin \(\displaystyle O\) and \(\displaystyle B\), which is \(\displaystyle (6, 4)\), as its endpoints.

The midpoint of a segment with endpoints at \(\displaystyle (x_{1}, y_{1})\) and \(\displaystyle (x_{2}, y_{2})\) is located at

\(\displaystyle \left ( \frac{x_{1}+x_{2}}{2}, \frac{y_{1}+y_{2}}{2} \right )\),

so, substituting the coordinates of \(\displaystyle O\) and \(\displaystyle B\) in the formula, we see that \(\displaystyle M\) is

\(\displaystyle \left ( \frac{0+6}{2}, \frac{0+4}{2} \right )\), or \(\displaystyle (3,2)\).

See the figure below:

1

To perform the translation \(\displaystyle A \rightarrow M\), or, equivalently,

\(\displaystyle (8, 0) \rightarrow (3,2)\),

on a point, it is necessary to add

\(\displaystyle 3-8 = -5\)

and

\(\displaystyle 2- 0 = 2\)

to the \(\displaystyle x\)- and \(\displaystyle y\)- coordinates, respectively. Therefore, the image of \(\displaystyle B\) is located at 

\(\displaystyle (6+ (-5), 4+ 2)\),

or

\(\displaystyle (1,6)\).

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