Hint
The angle is acute in the stated right triangle. Choose the appropriate side ratio, using a reciprocal where required.
Worked solution
(a)
Choose the appropriate side ratio, using a reciprocal where required.
\(\displaystyle \frac{15}{17}\)
Answer: \(\displaystyle \frac{15}{17}\)
(b)
Choose the appropriate side ratio, using a reciprocal where required.
\(\displaystyle \frac{8}{17}\)
Answer: \(\displaystyle \frac{8}{17}\)
(c)
Choose the appropriate side ratio, using a reciprocal where required.
\(\displaystyle \frac{15}{8}\)
Answer: \(\displaystyle \frac{15}{8}\)
Maths4U indicative marking guidance
Maths4U indicative marking guidance, not an official mark scheme. Credit complete valid alternatives and consequential reasoning; an unexplained final answer does not earn a method mark.
(a) · 2 marks
- 1 mark: Choose the appropriate side ratio, using a reciprocal where required.
- 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: The hypotenuse is always opposite the right angle.
(b) · 2 marks
- 1 mark: Choose the appropriate side ratio, using a reciprocal where required.
- 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: Do not interchange opposite and adjacent.
(c) · 2 marks
- 1 mark: Choose the appropriate side ratio, using a reciprocal where required.
- 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: The hypotenuse is always opposite the right angle.
Total: 6 marks.