Delta is the pronunciation of the fourth Greek letter. In Chinese, Delta is capitalized as δ and lowercase as δ. In mathematics or physics, the capitalized δ is used to represent the incremental symbol. And lowercase δ is usually used to represent variables or symbols in higher mathematics.

Delta is the English word for Delta, and it is shaped like a triangle, just like a capitalized Delta.

Letter meaning

1. In chemistry, the valence bond formed by overlapping two D orbitals is called delta bond, which can be abbreviated as "face to face". From the bond axis, there is no difference between the orbital symmetry of δ bond and the orbital symmetry of D orbit, and the Greek letter δ also comes from D orbit. It means charged: δ-means negatively charged and δ+means positively charged.

2. In mathematics, science and engineering technology, it is used to express the "change" of a certain quantity. For example:

① q = cm Δ t (where q stands for heat, c stands for specific heat [capacity] of matter, m stands for mass of matter, and Δ t stands for temperature change).

② f = k δ x (Hooke's Law) (where F stands for tension, K stands for spring stiffness coefficient (or stubbornness coefficient, δ x stands for spring elongation).

3. In algebra, the discriminant of polynomial equation or polynomial function. Where the unary quadratic equation ax2+bx+c=0(a≠0) or the quadratic function y=ax2+bx+c(a≠0), the discriminant is δ = B2-4ac.