Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now: https://www.khanacademy.org/math/multivariable-calculus/multivariable-derivatives/jacobian/v/jacobian-prerequisite-knowledge Before jumping into the Jacobian, it's important to make sure we all know how to think about matrices geometrically. This is targetted towards those who have seen linear algebra but may need a quick refresher.