Area of a square

The area of
a square equals the square of
the length of one side.

Catenary

Supported at each
end, a hanging cable forms
a catenary.

Complement of a set

A set’s complement:
everything not in the set
but in its domain.

Transitive property of equality

If A equals B,
and if B equals C, then
A must equal C.

[d/dx]sin(x)

The derivative
of the sine function equals
the cosine function.