Graph of y = cos(x)
The cosine graph is the sine wave shifted left by π/2: it starts at its maximum (0, 1), repeats every 2π, and crosses zero at π/2, 3π/2 and so on.
At a glance
| What it is | Graph y = cos(x) online and compare it with sin(x). Period 2π, amplitude 1, maximum at x = 0, zeros at π/2 + πn. Free graphing calculator. |
|---|---|
| Type | Interactive guide with a calculator |
| Level | High school and college |
| Price | Free, with no account or sign-up |
| Works offline | Yes, after the first visit; installs as an app |
| Made by | Aalok (aalok.builds@gmail.com) |
| Last updated | 1 November 2026 |
Key facts
| Period | 2π (360°) |
|---|---|
| Amplitude | 1 |
| Starts at | Its maximum, (0, 1) |
| Zeros | x = π/2 + πn |
| Relation to sine | cos(x) = sin(x + π/2) |
| Symmetry | Even function: mirror image in the y-axis |
How do sine and cosine compare?
Both waves are loaded above so you can see that cosine reaches each peak a quarter of a period (π/2) before sine does.
How to use it in Plotline
- The graph of y = cos(x) together with y = sin(x) is already loaded above. Edit the equation in the list to change it.
- Drag the graph to move around, scroll or pinch to zoom, and tap the crosshair to reset the view.
- Hover over or tap the curve to read the coordinates of any point.
- Press Enter to add another equation and compare graphs in different colors.
Frequently asked questions
Is cosine an even or odd function?
Cosine is even: cos(−x) = cos(x), so the graph is a mirror image across the y-axis. Sine is odd: sin(−x) = −sin(x), so its graph has rotational symmetry about the origin instead.
Is it free?
Yes. The graphing calculator is free with no account and no sign-up: plot as many equations as you like, use sliders, save graphs in your browser and share them by link. It installs as an app and keeps working offline.
Learn more
Related
- Sine graph – Graph y = sin(x) online.
- Tangent graph – Graph y = tan(x) online.
- Sin cos tan calculator – Free sin, cos and tan calculator in degrees or radians, with inverse trig.
Free calculators
- Graphing Calculator – Graph functions, circles, inequalities, polar and parametric equations instantly.
- Scientific Calculator – Free online scientific calculator with sin, cos, tan, inverse trig, logs, powers, roots, factorials, degrees and radians.
- Basic Calculator – A simple, free online calculator for add, subtract, multiply, divide, percent, square and square root.
- Matrix Calculator – Free matrix calculator: determinant, inverse, multiplication, transpose, RREF, rank, trace and powers, with exact fractions.
Plotline is an independent project and is not affiliated with Desmos, Texas Instruments or Casio.