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

Answer 1

Jacobian

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.

J is for Java

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.

Joint probability

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

Join

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.

Math Glossary

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 http://www.mathwords.com/jk/joint_variation.htm