What does delta mean in maths?

Answer 1

There are many meanings. The most common one is "change in". So delta x is the change in x. This form is often used in calculus where it means very small changes in x.

But there is also the Dirac delta function, a fundamental mathematical underpinning for quantum physics.

A delta can also be a quadrilateral which is otherwise known as an arrowhead.

Answer 2

Delta in math is generally symbolized as the triangle. Can mean, variation of a variable or function. However its meaning changes depending in the context.