Chapter 14 Trigonometric Graphs, Identities, and Equations - 14.7 Apply Double-Angle and Half-Angle Formulas - 14.7 Exercises - Skill Practice - Page 960: 34

$2 \sin \theta - \csc \theta$

Re-arrange as: $\cos 2 \theta =1- 2\sin^2 \theta $ or, $ -\dfrac{\cos 2 \theta}{\sin \theta}=- \dfrac{1- 2\sin^2 \theta }{ \sin \theta }$ or, $=- (\dfrac{1}{\sin \theta} - 2 \sin \theta)$ or, $=2 \sin \theta -\dfrac{1}{\sin \theta}$ or, $=2 \sin \theta - \csc \theta$