OpenStax, Precalculus 2e §7.3 Double-Angle, Half-Angle, and Reduction Formulas · Exercise 7 · Trigonometry · Compound & multiple angles

Double-Angle, Half-Angle, and Reduction Formulas · Exercise 7

Find the exact values of a) $s in (2 x),$ b) $cos (2 x),$ and c) $t an (2 x)$ without solving for $x .$

If $cos x = - \frac{1}{2},$ and $x$ is in quadrant III.

~8 minWritten answer · compare with the solution

OpenStax, Precalculus 2e · §7.3 Double-Angle, Half-Angle, and Reduction Formulas · Exercise 7

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