Are there any math or algebra words that start with J besides justification?

Java

Jacobian, for example. It's the matrix of first derivatives of a vector valued function with respect to all its arguments. For example, in statistics, when you transform a random vector, the density of the new vector is the density of the old one times the Jacobian.

These are kind of obscure applications, but Java programming falls under the umbrella of mathematics. And in electronics, and italicized lower case letter j is used to represent the value of the square root of negative 1.

In statistics, there is joint probability - the chance that 2 or more events occur together.

The join of two objects in a partially ordered set is their least upper bound - the smallest object above them both. This always exists in a join semilattice.

I found one mathematics glossary that lists some jargon and theorems that begin with the letter J. See the link to the right.

I can think of Jordan canonical form and j which is the unit vector (in one particular dimension) of a quaternion.

Go to Words.com/jk/joint_variation.htm">http://www.mathWords.com/jk/joint_variation.htm