Sine & Cosine Function Calculator
Analyze general trigonometric functions f(x) = a·sin(b(x-c))+d, determine amplitude, period, frequency, roots, extrema, use the interactive unit circle, and solve periodic modeling problems.
Parameters of the General Trigonometric Function
2D-Funktionsplotter
2D-Funktionsgraph & Schwingungsverlauf
Analysis (Ableitungen & Stammfunktion)
Kurvendiskussion (Punkte im Intervall)
Historical Origin & The Challenge Solved
Why was this mathematics developed, where does it come from, and what real-world problem did it solve?
1. Periodic Natural Phenomena & Oscillations
Ocean tides, planetary orbits, pendulums, and musical sounds repeat periodically. Classical linear mathematics could not continuously model smooth harmonic circular and wave motions.
2. Unit Circle Functions & Fourier Decomposition
Euler defined sine and cosine as continuous functions on the unit circle. In 1822, Joseph Fourier proved that ANY periodic oscillation (sound, heat, light) can be decomposed into a sum of pure sine and cosine waves.
3. MP3 Compression, Wi-Fi, 5G & MRI Scanners
Wireless telecommunications, Wi-Fi networks, MP3 audio compression, and MRI medical imaging function by converting complex waveforms into sine and cosine components.
Real-World Applications of Periodic Phenomena
Sine and cosine functions are the foundational mathematical language for modeling waves, oscillations, and cyclical natural cycles.
Ferris Wheel Modeling (Grade 10 Standard)
The height of a cabin above the ground follows a cosine oscillation h(t) = -r·cos(ωt) + h_center with radius r and center axle height h_center.
Ferris wheel with radius 15 m, axle height 18 m, and 30 s rotation period: h(t) = -15·cos((π/15)t) + 18.
Ocean Tides (Ebb and Flood)
Periodic ocean water levels caused by the Moon's gravitational pull are modeled with a sine curve having a period of p ≈ 12.4 hours.
Average depth 3.5 m with tidal range 3.6 m (amplitude 1.8 m): W(t) = 1.8·sin((2π/12.4)t) + 3.5.
Sound Waves & AC Voltage
Musical notes like concert pitch A (440 Hz) and household electrical grid voltage (120V / 230V, 50/60 Hz) are pure sine oscillations y(t) = A·sin(2π·f·t).
Grid AC voltage with peak value 325 V: u(t) = 325·sin(100π·t) V.
Mathematical Guide to General Sine and Cosine Functions
The general sinusoidal model f(x) = a·sin(b(x-c))+d extends triangle trigonometry to continuous real-valued periodic oscillations.
Amplitude |a| & Midline d
The amplitude |a| specifies maximum upward and downward displacement. Parameter d shifts the wave vertically (midline y = d). Range: 𝕎 = [d-|a|; d+|a|].
Frequency Factor b & Period p
Factor b compresses (b > 1) or stretches (b < 1) the wave horizontally. The period is p = 2π / |b| (in degrees: p = 360° / |b|). Angular frequency is ω = |b|.
Phase Shift c
Parameter c shifts the graph horizontally: (x - c) shifts right, (x + c) shifts left. Note that cos(x) = sin(x + π/2).
Derivative & Integral Cycle
In radians, the derivative cycle is: sin(x) → cos(x) → -sin(x) → -cos(x) → sin(x). With chain rule: (a·sin(b(x-c)))' = a·b·cos(b(x-c)).
Frequently Asked Questions (FAQ) on Sine and Cosine Functions
What is the key difference between sine and cosine?▼
Cosine is simply a sine wave shifted left by 90° (or π/2 radians): cos(x) = sin(x + π/2). Both have identical amplitude, frequency, and wave shape.
When should I use radians (rad) vs degrees (°)?▼
In calculus, differentiation, and physics, radians are mandatory because only in radians does (sin x)' = cos x hold without conversion factors. Degrees are often used in introductory geometry.
How do you solve an equation like sin(x) = 0.5 in [0; 2π]?▼
1. Principal value via arcsine: x₁ = arcsin(0.5) = π/6 (30°). 2. Symmetric value in Quadrant II: x₂ = π - x₁ = 5π/6 (150°). Add multiples of the period + k·2π for all solutions.
How do you build a sinusoidal function for a Ferris wheel?▼
Amplitude a = radius r, midline d = axle height = bottom height + r, period p = rotation time T, b = 2π/T. If the cabin starts at the bottom, use -r·cos((2π/T)t) + d.
Why is the derivative of sin(x) equal to cos(x)?▼
At x=0, the sine curve reaches its steepest slope 1 (cos(0) = 1), and at peaks x=π/2 the slope is 0 (cos(π/2) = 0). Plotting these tangent slopes yields the cosine wave.