Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.

Lesson: Rotation and Reflection Matrices

Worksheet • 12 Questions

Q1:

Find the matrix with respect to the standard basis vectors for the linear transformation that rotates every vector in ℝ 2 through an angle of πœ‹ 3 and then reflects it across the 𝑦 -axis.

  • A βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ 1 2 √ 3 2 √ 3 2 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 1 2 1 2 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 1 2 √ 3 2 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎜ ⎝ 1 2 βˆ’ √ 3 2 √ 3 2 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎝ 1 2 √ 3 2 √ 3 2 1 2 ⎞ ⎟ ⎟ ⎟ ⎠

Q2:

A linear transformation is formed by reflecting every vector in ℝ 2 in the 𝑦 -axis and then rotating the resulting vector through an angle of πœ‹ 4 . Find the matrix of this linear transformation.

  • A βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 2 2 βˆ’ √ 2 2 βˆ’ √ 2 2 √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 2 2 0 0 √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 2 2 √ 2 2 βˆ’ √ 2 2 √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎜ ⎝ √ 2 2 βˆ’ √ 2 2 √ 2 2 √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 2 2 √ 2 2 √ 2 2 √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠

Q3:

A linear transformation is formed by rotating every vector in ℝ 2 through an angle of πœ‹ 6 , reflecting the resulting vector in the π‘₯ -axis, and finally reflecting this vector in the 𝑦 -axis. Find the matrix of this linear transformation.

  • A βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 1 2 βˆ’ 1 2 βˆ’ √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 0 0 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 βˆ’ 1 2 1 2 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 1 2 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 βˆ’ 1 2 βˆ’ √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠

Q4:

A linear transformation is formed by rotating every vector in ℝ 2 through an angle of 2 πœ‹ 3 and then reflecting the resulting vector in the π‘₯ -axis. Find the matrix of this linear transformation.

  • A βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ 1 2 βˆ’ √ 3 2 βˆ’ √ 3 2 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎝ 1 2 βˆ’ √ 3 2 βˆ’ √ 3 2 βˆ’ 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ 1 2 √ 3 2 βˆ’ √ 3 2 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎝ βˆ’ 1 2 0 0 1 2 ⎞ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ 1 2 βˆ’ √ 3 2 √ 3 2 βˆ’ 1 2 ⎞ ⎟ ⎟ ⎟ ⎠

Q5:

A linear transformation is formed by reflecting every vector in ℝ 2 across the 𝑦 -axis and then rotating the resulting vector through an angle of πœ‹ 6 . Find the matrix of this linear transformation.

  • A βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 βˆ’ 1 2 βˆ’ 1 2 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 0 0 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 1 2 βˆ’ 1 2 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 1 2 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ √ 3 2 1 2 1 2 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠

Q6:

A linear transformation is formed by rotating every vector in ℝ 2 through an angle of πœ‹ 3 and then reflecting the resulting vector in the π‘₯ -axis. Find the matrix of this linear transformation.

  • A βŽ› ⎜ ⎜ ⎜ ⎝ 1 2 βˆ’ √ 3 2 βˆ’ √ 3 2 βˆ’ 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎝ βˆ’ 1 2 βˆ’ √ 3 2 βˆ’ √ 3 2 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎝ 1 2 √ 3 2 βˆ’ √ 3 2 βˆ’ 1 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎝ 1 2 0 0 βˆ’ 1 2 ⎞ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎝ 1 2 βˆ’ √ 3 2 √ 3 2 1 2 ⎞ ⎟ ⎟ ⎟ ⎠

Q7:

A linear transformation is formed by reflecting every vector in ℝ 2 in the π‘₯ -axis and then rotating the resulting vector through an angle of πœ‹ 6 . Find the matrix of this linear transformation.

  • A βŽ› ⎜ ⎜ ⎜ ⎝ √ 3 2 1 2 1 2 βˆ’ √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎝ √ 3 2 0 0 βˆ’ √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 1 2 βˆ’ √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 1 2 √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 βˆ’ 1 2 βˆ’ √ 3 2 ⎞ ⎟ ⎟ ⎟ ⎠

Q8:

A linear transformation is formed by reflecting every vector in ℝ 2 in the π‘₯ -axis and then rotating the resulting vector through an angle of πœ‹ 4 . Find the matrix of this linear transformation.

  • A βŽ› ⎜ ⎜ ⎜ ⎝ √ 2 2 √ 2 2 √ 2 2 βˆ’ √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎝ √ 2 2 0 0 βˆ’ √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎝ √ 2 2 βˆ’ √ 2 2 √ 2 2 βˆ’ √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎜ ⎝ √ 2 2 βˆ’ √ 2 2 √ 2 2 √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎝ √ 2 2 βˆ’ √ 2 2 βˆ’ √ 2 2 βˆ’ √ 2 2 ⎞ ⎟ ⎟ ⎟ ⎠

Q9:

Let the matrix represent rotation in the plane through an angle of and let the matrix represent reflection in the -axis.

What is the matrix ?

  • A
  • B
  • C
  • D
  • E

What is the matrix ?

  • A
  • B
  • C
  • D
  • E

What is the matrix ?

  • A
  • B
  • C
  • D
  • E

Q10:

Suppose that the matrix represents rotation about the origin through an angle of (measuring between and ) and the matrix represents reflection in the -axis.

Find .

  • A
  • B
  • C
  • D
  • E

Note that is a reflection in a line through the origin. Let this line of reflection have equation . By considering the image of the vector , determine the measure of the angle between the -axis and the line of reflection.

  • A
  • B
  • C
  • D
  • E

What, therefore, is the slope of the line of reflection?

  • A
  • B
  • C
  • D
  • E

If lies in the direction of the line of reflection, what is ?

  • A
  • B
  • C
  • D
  • E

By solving the equation obtained in the previous part, find another expression for the slope of the line of reflection.

  • A
  • B
  • C
  • D
  • E

Q11:

Consider the given figure.

The points , , , and are corners of the unit square. This square is reflected in the line with equation to form the image .

As is the image of in the line through and , . Use this fact and the identity to find the gradient and hence equation of from the gradient of .

  • A
  • B
  • C
  • D
  • E

Using the fact that is perpendicular to , find the equation of .

  • A
  • B
  • C
  • D
  • E

Using the fact that , find the coordinates of and .

  • A ,
  • B ,
  • C ,
  • D ,
  • E ,

Using the fact that a reflection in a line through the origin is a linear transformation, find the matrix which represents reflection in the line .

  • A
  • B
  • C
  • D
  • E

Q12:

A linear transformation is formed by rotating every vector in ℝ 3 through an angle of 3 0 ∘ counterclockwise (when viewed from the positive 𝑧 -axis) about the 𝑧 -axis and then reflecting the resulting vector in the π‘₯ 𝑦 -plane. Find the matrix of this linear transformation.

  • A βŽ› ⎜ ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 0 1 2 √ 3 2 0 0 0 βˆ’ 1 ⎞ ⎟ ⎟ ⎟ ⎟ ⎠
  • B βŽ› ⎜ ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 0 βˆ’ 1 2 βˆ’ √ 3 2 0 0 0 βˆ’ 1 ⎞ ⎟ ⎟ ⎟ ⎟ ⎠
  • C βŽ› ⎜ ⎜ ⎜ ⎜ ⎝ 1 2 βˆ’ √ 3 2 0 √ 3 2 1 2 0 0 0 βˆ’ 1 ⎞ ⎟ ⎟ ⎟ ⎟ ⎠
  • D βŽ› ⎜ ⎜ ⎜ ⎜ ⎝ 1 2 βˆ’ √ 3 2 0 √ 3 2 1 2 0 0 0 1 ⎞ ⎟ ⎟ ⎟ ⎟ ⎠
  • E βŽ› ⎜ ⎜ ⎜ ⎜ ⎝ √ 3 2 βˆ’ 1 2 0 1 2 √ 3 2 0 0 0 1 ⎞ ⎟ ⎟ ⎟ ⎟ ⎠
Preview