Hint
Use the stated units and precision. Add only the disjoint regions described by the set expression.
Worked solution
(a)
Add only the disjoint regions described by the set expression.
\(19\)
Answer: \(19\)
(b)
Add only the disjoint regions described by the set expression.
\(5\)
Answer: \(5\)
(c)
Add only the disjoint regions described by the set expression.
\(9\)
Answer: \(9\)
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: Add only the disjoint regions described by the set expression.
- 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: Add only the disjoint regions described by the set expression.
- 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: Add only the disjoint regions described by the set expression.
- 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.