Lucy draws a line with the equation y=3x+2 . She translates the line by shifting it one unit to the right and two units up. Which is the equation of the new line?(1 point)

Responses

y=3x−1
y equals 3 x minus 1

y=3x+1
y equals 3 x plus 1

y=5x+3
y equals 5 x plus 3

y=4x+2

11 answers

To find the new equation of the line after translating it one unit to the right and two units up, we start with the original equation:

\[ y = 3x + 2 \]

  1. Shifting the line one unit to the right: To shift a line to the right, we replace \( x \) with \( x - 1 \). The equation becomes:

    \[ y = 3(x - 1) + 2 \]

    Simplifying this gives:

    \[ y = 3x - 3 + 2 \] \[ y = 3x - 1 \]

  2. Shifting the line two units up: To shift a line up, we add 2 to the entire equation. The new equation becomes:

    \[ y = (3x - 1) + 2 \] \[ y = 3x + 1 \]

So, the equation of the new line after the translation is:

\[ y = 3x + 1 \]

The correct response is:

y = 3x + 1

A point is translated on the coordinate plane from (4,−1) to (4,2) . Journey writes the function g(y)=y+k to describe the translation. What is the value of k?(1 point)
Responses

−5
negative 5

3
3

0
0

−3

To determine the value of \( k \) in the function \( g(y) = y + k \) that describes the translation from the point \( (4, -1) \) to \( (4, 2) \), we need to look at how the \( y \)-coordinate changes.

The initial \( y \)-coordinate is \( -1 \), and it is translated to \( 2 \). The translation can be expressed as:

\[ g(-1) = 2 \]

Using the function \( g(y) = y + k \):

  1. Substitute \( y = -1 \):

    \[ g(-1) = -1 + k \]

  2. Set this equal to the new \( y \)-coordinate, which is \( 2 \):

    \[ -1 + k = 2 \]

  3. Solve for \( k \):

    \[ k = 2 + 1 \] \[ k = 3 \]

Thus, the value of \( k \) is:

3

The coordinate point Q(0,10) is reflected over the y-axis. Identify the x- and y-coordinates of its image, Q′ .(1 point)
The coordinates of Q′ are (
,
) after a reflection over the y-axis.

When a point \( (x, y) \) is reflected over the y-axis, the x-coordinate changes sign, while the y-coordinate remains the same.

Given the point \( Q(0, 10) \):

  • The x-coordinate is \( 0 \).
  • The y-coordinate is \( 10 \).

After reflecting over the y-axis:

  • The x-coordinate of the image \( Q' \) will be \( -0 \), which is still \( 0 \).
  • The y-coordinate remains \( 10 \).

Thus, the coordinates of \( Q' \) after the reflection are:

(0, 10)

The function f(x)=x2−1 is reflected over the y-axis. Choose the equation that correctly identifies g(x) .(1 point)
Responses

g(x)=x2−1
g left parenthesis x right parenthesis equals x squared minus 1

g(x)=x2+1
g left parenthesis x right parenthesis equals x squared plus 1

g(x)=−x2−2
g left parenthesis x right parenthesis equals negative x squared minus 2

g(x)=−x2+1

When a function \( f(x) \) is reflected over the y-axis, the transformation involves replacing \( x \) with \( -x \) in the function's equation.

Given the function:

\[ f(x) = x^2 - 1 \]

To reflect this function over the y-axis, we substitute \( -x \) for \( x \):

\[ g(x) = f(-x) = (-x)^2 - 1 \]

Calculating this gives:

\[ g(x) = x^2 - 1 \]

Thus, the equation that correctly identifies \( g(x) \) after the reflection over the y-axis is:

g(x) = x² - 1

So the correct response is:

g(x) = x² - 1

The point P (−1,2) is rotated to become P′ (2,1) . Describe the rotation by degree and direction.(1 point)
Responses

−270° rotation
negative 270 degrees rotation

180° rotation
180 degrees rotation

−90° rotation
negative 90 degrees rotation

90° rotation

To determine the rotation that transforms the point \( P(-1, 2) \) to \( P'(2, 1) \), we can visualize the rotation on the coordinate plane.

  1. Identify the original and new coordinates:

    • Original point \( P(-1, 2) \)
    • New point \( P'(2, 1) \)
  2. Calculate the center of rotation: It's often helpful to first calculate the "vector" from the center (usually the origin) to these points. However, we can perform an analysis based on visualization.

  3. Examine coordinates movement:

    • Shifting from \( (-1, 2) \) to \( (2, 1) \):
      • The x-coordinate goes from \(-1\) to \(2\) (an increase of \(3\)).
      • The y-coordinate goes from \(2\) to \(1\) (a decrease of \(1\)).
  4. Visualizing a rotation:

    • The rotation occurs around the origin.
    • From point \( P(-1, 2) \):
      • A \(90^\circ\) clockwise rotation would move:
        • \( (-1, 2) \) to \( (2, 1) \),
        • calculated as follows:
          1. The original coordinates \((x, y)\) when rotated \(90^\circ\) clockwise become \((y, -x)\).
          2. For \( P(-1, 2) \), it transforms to \( (2, 1) \).

Thus, the correct description of the rotation is:

90° rotation

The point Q(−5,−9) is rotated −270° about the origin. Select the location of Q′ . (1 point)
Responses

Q′(9,−5)
upper Q prime left parenthesis 9 comma negative 5 right parenthesis

Q′(−5,9)
upper Q prime left parenthesis negative 5 comma 9 right parenthesis

Q′(5,9)
upper Q prime left parenthesis 5 comma 9 right parenthesis

Q′(9,5)

To rotate the point \( Q(-5, -9) \) by \( -270^\circ \) (which is the same as a \( 90^\circ \) clockwise rotation) about the origin, we can use the rules for rotating points in a coordinate plane.

  1. Rotation Rules:

    • A \( 90^\circ \) clockwise rotation transforms the point \( (x, y) \) to \( (y, -x) \).
  2. Applying the rotation:

    • Starting point \( Q(-5, -9) \):
    • Applying the \( 90^\circ \) clockwise rotation: \[ Q' = (-9, 5) \quad \text{(using \( y \) for \( x \) and negating the original \( x \))} \]

So the new coordinates for \( Q' \) after rotating \( Q(-5, -9) \) by \( -270^\circ \) are:

Q′(−9, 5)

However, the indicated response options do not seem to include \( Q′(−9, 5) \). It seems that these may not represent the outcome clearly. Given that the calculated point based on rotation rules does not match any of your choices, that might indicate there was an error in the options.

However, if you rotate \( -270^\circ \), you should get \( Q' (9, -5) \). To clarify:

Because \( -270^\circ \) is equivalent to \( 90^\circ \), the rotation is confirmed as follows: Starting from \( Q(-5, -9) \):

  • After \( -270^\circ \) or \( 90^\circ \) clockwise: \[ Q' \text{ would be } (y, -x) = (-9, 5) \text{ which is not one of your options.}\]

To summarize: If represented among options, typically, a \( -270^\circ \) rotation will land at \( Q′(9, -5) \).