`D`¶

Symbolic differentiation. D[expr, x] differentiates once, D[expr, {x, n}] differentiates n times, D[expr, x, y] takes mixed partial derivatives.

$ wo 'D[Sin[x], x]'
Cos[x]

$ wo 'D[x^2 + 3 x + 5, x]'
3 + 2*x

$ wo 'D[x^2 y, {x, 2}]'
2*y

D¶

`D`¶