BUILD FLUENCY. EARN YOUR ASCENT.Sign in Start practising10 questions · No timer · No account needed Practise the method.
Coordinate enlargements and invariants
Coordinate enlargements and invariants
Example 1
Enlarge P=(1,3) by scale factor 5 about (0,0). Find the image coordinates.
Show worked answer
Answer: (5,15)
- Subtract the centre, multiply by 5, then add the centre: (0+5(1−0),0+5(3−(0))).
Example 2
Enlarge P=(1,3) by scale factor 5 about (1,−1). Find the image coordinates.
Show worked answer
Answer: (1,19)
- Subtract the centre, multiply by 5, then add the centre: (1+5(1−1),−1+5(3−(−1))).
Example 3
A shape is enlarged by linear scale factor 2. By what factor does its area change?
Show worked answer
Answer: 4
- Each of two dimensions is multiplied by 2, so area is multiplied by 22=4.
Put it into practice.
Try a fresh round with worked feedback. Create an account whenever you want to save future progress.