Exam-Style Question on Trigonometric Identities
A mathematics exam-style question with a worked solution that can be revealed gradually
Question id: 557. This question is similar to one that appeared on an IB AA Standard paper in 2021. The use of a calculator is not allowed.
(a) Show that:$$ \cos 2x - \sin 2x + 1 = 2 \cos x ( \cos x - \sin x) $$
(b) Hence or otherwise, solve the following equation for \( \pi \lt x \lt 3\pi \).$$ \cos 2x - \sin 2x + 1 = \sin x - \cos x $$
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