Invariants Under Transformation Math Example 2
Follow the full solution, then compare it with the other examples linked below.
Example 2
mediumA rectangle with vertices , , , is dilated by a scale factor of centered at the origin. Which properties are invariant and which change?
Solution
- 1 Apply dilation: multiply each coordinate by . New vertices: , , , .
- 2 Original side lengths: and . New side lengths: and . Side lengths are NOT invariant ā they doubled.
- 3 Original angles: all . New angles: all . Angles ARE invariant under dilation.
- 4 Original area: . New area: . Area scales by so it is NOT invariant.
- 5 The ratio of sides: and . Ratios of corresponding lengths ARE invariant.
Answer
Dilation is a similarity transformation. It preserves angle measures and the ratios of corresponding lengths, but changes actual distances by the scale factor and areas by . The shape is preserved but not the size.
About Invariants Under Transformation
A property of a function is invariant under a transformation if it remains unchanged after the transformation is applied to the function.
Learn more about Invariants Under Transformation āMore Invariants Under Transformation Examples
Example 1 easy
A triangle with vertices at [formula], [formula], and [formula] is translated by the vector [formula
Example 3 mediumA figure is reflected over the [formula]-axis. Determine whether each property is invariant: (a) sid
Example 4 hardUnder a shear transformation defined by [formula], determine whether the area of a unit square with