Constants and operators

Written out, a Greek letter is drawn as the letter. It is a name like any other: it may be defined, used as a parameter, or left undefined for Desmos to offer as a slider.

Name	Letter
`alpha`	α
`beta`	β
`gamma`	γ
`delta`	δ
`epsilon`	ε
`zeta`	ζ
`eta`	η
`iota`	ι
`kappa`	κ
`lambda`	λ
`mu`	μ
`nu`	ν
`xi`	ξ
`rho`	ρ
`sigma`	σ
`phi`	φ
`chi`	χ
`psi`	ψ
`omega`	ω
`Gamma`	Γ
`Delta`	Δ
`Theta`	Θ
`Lambda`	Λ
`Xi`	Ξ
`Pi`	Π
`Sigma`	Σ
`Phi`	Φ
`Psi`	Ψ
`Omega`	Ω

Operators

Words Desmos reads as operators rather than as functions or variables. None of them takes parentheses.

width

Viewport width, in graph units

Follows the viewport as it is panned and zoomed.

x = width / 4

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height

Viewport height, in graph units

Follows the viewport as it is panned and zoomed.

y = height / 4

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for

List comprehension: [i ^ 2 for i = [1…10]]

Builds a list by running the expression before it over every element of a list. More than one binding, for i = A, j = B, runs over every pair.

S = [i ^ 2 for i = [1...10]]
[(i, i ^ 2) for i = [1...5]]

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with

Local definition: f(x) = x n with n = length(a)

Substitutes values into the expression before it. The bindings run to the end of the bracket or statement.

y = a x ^ 2 with a = 0.5

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index

The element’s 1-based position, inside a list filter or a clickable action

Which element of a list was clicked, counting from 1.

n = 0
P = [(1, 1), (2, 2), (3, 3)] @ onClick: n -> index, pointSize: 20

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dt

Milliseconds since the last tick - only valid in a ticker handler

Written anywhere but the ticker’s handler it is an error, dt-outside-ticker.

n = 0
ticker n -> n + dt @ playing

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