OpenStax, Precalculus 2e §7.3 Double-Angle, Half-Angle, and Reduction Formulas · Exercise 28 · Trigonometry · Compound & multiple angles

Double-Angle, Half-Angle, and Reduction Formulas · Exercise 28

Simplify each expression. Do not evaluate.

$co s^{2} (2 8^{\circ}) - s i n^{2} (2 8^{\circ})$

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OpenStax, Precalculus 2e · §7.3 Double-Angle, Half-Angle, and Reduction Formulas · Exercise 28

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