The sequence of transformations, [tex]\( R_{0,90^{\circ}} \)[/tex] followed by [tex]\( r_{X \text{-axis}} \)[/tex], is applied to [tex]\(\Delta XYZ\)[/tex] to produce [tex]\(\Delta X'Y'Z'\)[/tex]. If the coordinates of [tex]\( Y'' \)[/tex] are [tex]\((3,0)\)[/tex], what are the coordinates of [tex]\( Y \)[/tex]?

[tex]\( Y \)[/tex] [tex]\( \square \)[/tex]
[tex]\( \square \)[/tex]



Answer :

Let's break down the sequence of transformations and apply them step-by-step to find the coordinates of point [tex]\( Y \)[/tex].

### Given:
1. The final coordinates of [tex]\( Y'' \)[/tex] are [tex]\( (3, 0) \)[/tex].
2. The transformation sequence is [tex]\(R_{0,90^\circ} r_{X \text{ -axis }}\)[/tex].

### Steps:

1. First Transformation: Reflection over the X-axis

The reflection over the X-axis changes the [tex]\(y\)[/tex]-coordinate of a point while keeping the [tex]\(x\)[/tex]-coordinate the same. Let's apply this to [tex]\( Y'' \)[/tex]:

[tex]\[ Y'' = (3, 0) \][/tex]
The reflection over the X-axis is:
[tex]\[ (x, y) \rightarrow (x, -y) \][/tex]
Applying this transformation:
[tex]\[ Y' = (3, -0) = (3, 0) \][/tex]

2. Second Transformation: Rotation by 90 degrees about the origin

The 90-degree rotation about the origin swaps the [tex]\( x \)[/tex] and [tex]\( y \)[/tex] coordinates and changes the sign of the [tex]\( y \)[/tex]-coordinate (the new [tex]\( x \)[/tex]-coordinate). Let's apply this to [tex]\( Y' \)[/tex]:

[tex]\[ Y' = (3, 0) \][/tex]
The 90-degree rotation about the origin is:
[tex]\[ (x, y) \rightarrow (-y, x) \][/tex]
Applying this transformation:
[tex]\[ Y = (-0, 3) = (0, 3) \][/tex]

### Conclusion:
The coordinates of [tex]\( Y \)[/tex] after applying the transformations are [tex]\((0, 3)\)[/tex].

So, the coordinates of [tex]\( Y \)[/tex] are:
[tex]\[ Y \ ( \ 0, \ 3 \ ) \][/tex]