Matrices

Question 1

What are invariant lines and points for reflection in y axis

Answer 1

Invariant points in reflection in y axis are points on y axis and lines are x=0 and y=k

Question 2

What are invariant lines and points for reflection in x axis

Answer 2

Invariant points for reflection in x axis are points on x axis and lines are y=0 and x=k

Question 3

What are invariant lines and points for reflection in y=x

Answer 3

Invariant points in reflection in y=x are points on y=x and lines are y=x and y=-x+k

Question 4

What are invariant points and lines under reflection in y=-x

Answer 4

Invariant points in reflection y=-x are points on y=-x and lines y=-x and y=x+k

Question 5

What does determinant of matrix represent

Answer 5

Determinant of matrix represents scale factor for change in area (area scale factor), in 3D represents volume scale factor