OpenStax, Algebra and Trigonometry 2e §9.3 Double-Angle, Half-Angle, and Reduction Formulas · Exercise 6 · Trigonometry · Compound & multiple angles

Double-Angle, Half-Angle, and Reduction Formulas · Exercise 6

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 $cos x = \frac{2}{3},$ and $x$ is in quadrant I.

Its source prints no answer for this problem, so there's nothing to check against.

~8 minWritten answer · compare with the solution

OpenStax, Algebra and Trigonometry 2e · §9.3 Double-Angle, Half-Angle, and Reduction Formulas · Exercise 6

Stuck? A gentle nudge

No hints for this one.

Something off?

Workspace

Your working

Check your full solution

Upload photos of your handwritten work or a PDF, and Lemma will read it and tell you whether it's right — and where it first goes wrong if not.