https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:trig/x9e81a4f98389efdf:trig-id/v/trigonometry-unit-circle-symmetry 2021-05-05T14:53:18Z Sine & cosine identities: symmetry Sal finds several trigonometric identities for sine and cosine by considering horizontal and vertical symmetries of the unit circle. Sal Khan video https://cdn.kastatic.org/googleusercontent/hX3WT_E5jPWwlXRobWPxGJq4OYInNRchN78MjUoOWRLZ23yRk-N961XQLvHLPtx2NymQIUgGR3tt9gH8UrMZy3qZQA Sine & cosine identities: symmetry Sal finds several trigonometric identities for sine and cosine by considering horizontal and vertical symmetries of the unit circle. https://cdn.kastatic.org/ka-youtube-converted/tzQ7arA917E.mp4/tzQ7arA917E.mp4 478 Trigonometric identities on the unit circle https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:trig/x9e81a4f98389efdf:trig-id/v/tan-symmetries-unit-circle 2021-05-05T14:53:19Z Tangent identities: symmetry Sal finds several trigonometric identities for tangent by considering horizontal and vertical symmetries of the unit circle. Sal Khan video https://cdn.kastatic.org/googleusercontent/aJtG2MsWehGm34mtnN3fAUg8BPOp0PGeiziyIRmQaK4Ebf6XpWlPiE20cqN1fkmi3chWHluIhcbuH_MBKkj_7IrQ Tangent identities: symmetry Sal finds several trigonometric identities for tangent by considering horizontal and vertical symmetries of the unit circle. https://cdn.kastatic.org/ka-youtube-converted/k_wJsio68D4.mp4/k_wJsio68D4.mp4 435 Trigonometric identities on the unit circle https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:trig/x9e81a4f98389efdf:trig-id/v/trig-angle-rotations 2021-05-05T14:53:17Z Sine & cosine identities: periodicity Sal finds trigonometric identities for sine and cosine by considering angle rotations on the unit circle. Sal Khan video https://cdn.kastatic.org/googleusercontent/8R9ptji40BAkC_jOzCeGm6Fcnoe-QabEA_HoLfqCyjc0pTzHeTD_nCa92YdE8v1RV1B176jw6mZzX53nxrTkLjqx Sine & cosine identities: periodicity Sal finds trigonometric identities for sine and cosine by considering angle rotations on the unit circle. https://cdn.kastatic.org/ka-youtube-converted/h-TPSylHrvE.mp4/h-TPSylHrvE.mp4 373 Trigonometric identities on the unit circle https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:trig/x9e81a4f98389efdf:trig-id/v/tan-periodicity 2021-05-05T14:53:17Z Tangent identities: periodicity Sal solves a problem by considering the periodicity of the tangent function. Sal Khan video https://cdn.kastatic.org/googleusercontent/5syk7G_FmY-hYDAt88Z5TlQSkzxwSrnumrebAKIXOM2UegBtXO_8qFabPmW7WxnYvRCzlPDcYN8JgVexBKAcx5c Tangent identities: periodicity Sal solves a problem by considering the periodicity of the tangent function. https://cdn.kastatic.org/ka-youtube-converted/C3HFAyigqoY.mp4/C3HFAyigqoY.mp4 242 Trigonometric identities on the unit circle https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:trig/x9e81a4f98389efdf:trig-id/e/trig-identities-from-reflections-and-rotations 2026-05-12T22:10:47.015864082Z Trig identities from reflections and rotations Given the value of a trigonometric function for an angle x, use the unit circle to find the value for related angle measures. exercise https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:trig/x2ec2f6f830c9fb89:special-angles/e/trigonometric-functions-of-special-angles 2025-03-01T15:52:37.13987578Z Trig values of special angles Find the sine and cosine of special angles, which are angles whose trig values we can determine without the use of a calculator. Sulinya Ramanan exercise