Hint
Use the stated units and precision. Scale the relative horizontal displacement from the stated centre.
Worked solution
(a)
Scale the relative horizontal displacement from the stated centre.
Multiply the displacement 2 by \(\displaystyle \frac{1}{2}\) and add centre coordinate 0, giving \(1\).
Answer: \(1\)
(b)
Scale the relative vertical displacement from the stated centre.
Multiply the displacement 7 by \(\displaystyle \frac{1}{2}\) and add -3, giving \(\displaystyle \frac{1}{2}\).
Answer: \(\displaystyle \frac{1}{2}\)
(c)
Use the magnitude of the scale factor for a positive length.
Lengths use |k|, giving \(1\) cm.
Answer: \(1\)
Maths4U indicative marking guidance
Maths4U indicative marking guidance, not an official mark scheme. Credit complete valid alternative methods and consequential reasoning. An unexplained result does not earn a method mark.
(a) · 2 marks
- 1 mark: Scale the relative horizontal displacement from the stated centre.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
(b) · 2 marks
- 1 mark: Scale the relative vertical displacement from the stated centre.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Check the answer against the original conditions.
(c) · 2 marks
- 1 mark: Use the magnitude of the scale factor for a positive length.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
Total: 6 marks.