레슨
sin(pi/3)
Core
Trigonometric equations
Reference angles and the infinitely many solutions.
sin(x) = 1/2
Core
Trigonometric identities
Pythagorean, double-angle and sum identities, verified by simplification.
simplify sin(x)^2 + cos(x)^2
Introductory
Degrees and radians
Two ways to measure an angle, and converting between them.
30 degrees to radians
Core
Right-triangle trigonometry (SOH-CAH-TOA)
Sine, cosine and tangent as side ratios, and solving right triangles.
hypotenuse of 5 and 12
Core
Law of sines and law of cosines
Solving any triangle from three pieces of information.
triangle 5 7 with angle 60
Core
Graphs of sine, cosine and tangent
Amplitude, period, phase shift and the shape of periodic motion.
y = sin(x) + cos(2x)
Core
Inverse trigonometric functions
arcsin, arccos, arctan (which angle has this ratio) and their derivatives.
derivative of arctan(x)
Trigonometry is the geometry of the circle written as functions. Exact values from the unit circle, equations with infinitely many solutions, and the identities that make them tame.
더 많은 레슨
Trigonometric Identities and Equations
Trigonometric Functions
Periodic Functions
Further Applications of Trigonometry
The functions
Identities and triangles
이러한 교훈 중 일부는 개방된 텍스트에서 적용됩니다. OpenStax Algebra and Trigonometry 2e, OpenStax Precalculus 2e, Wikipedia. 각 레슨 페이지는 소스와 라이선스를 명시합니다.
여기서 사용된 기호
기호를 탭하면 전체 정의, 이미지 및 각 문자의 의미를 확인할 수 있습니다.
사람들이 묻는 질문
Why radians instead of degrees?
A radian is the angle whose arc equals the radius, so it is a pure ratio rather than an arbitrary 1/360 of a turn. With radians the derivative of sin x is exactly cos x; with degrees a factor of π/180 appears everywhere.
Why does sin x = 1/2 have infinitely many solutions?
Sine repeats every full turn, and within one turn it reaches 1/2 twice (at π/6 and 5π/6). Add any whole number of turns to either and it is still true.
How do I remember the exact values?
Two triangles: the 45-45-90 with sides 1, 1, √2 and the 30-60-90 with sides 1, √3, 2. Every value for 30°, 45° and 60° is a ratio of those sides; symmetry gives the rest of the circle.
솔버 페이지에 답을 입력하거나 그려보세요. 모든 단계, 그림, 답은 질문할 때까지 숨겨져 있습니다. 해결 →
다른 지점
＋ Arithmetic𝑥 Algebra△ Geometryƒ Precalculusσ Statistics & Probability⊢ Discrete Math & Logic∫ Calculus⊞ Linear Algebraℕ Number Theoryẏ Differential Equations∇ Multivariable Calculusε Real Analysis⋔ Combinatorics & Graph Theory∈ Set Theory & Logic𝔾 Abstract Algebra𝑃 Probability Theory≈ Numerical Methodsℂ Complex Analysis◎ Topologyμ Measure Theory‖·‖ Functional Analysisκ Differential Geometryπ₁ Algebraic Topology→ Category Theory∂ Partial Differential Equations≋ Fluid Dynamics∞ Frontiers