Practice variation 2 of 3
Trigonometric identity — Sine with half-scale roots
Your question
(i) Show that .
(ii) By letting in the cubic equation , show that .
(iii) Prove that .
This practice question was inspired by Question 14(b) in the 2020 NSW HSC Mathematics Extension 1 examination, © NESA. It is an original TestMum variation that practises the same mathematical idea, not an official NESA question.
Before you check
- Have you stated every choice or assumption?
- Can another student follow each line?
- Did you verify the final result independently?