Exam-Style Question on Trigonometric Identities
A mathematics exam-style question with a worked solution that can be revealed gradually
Question id: 577. 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 the equation \( 2 \sin^2 x - 5 \cos x = -1\) may be written in the form \( 2 \cos^2 x + 5 \cos x = 3\)
(b) Hence, solve the equation \( 2 \sin^2 x - 5 \cos x = -1 \), \( 2\pi \lt x \lt 4\pi \).
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