## What is a delta symbol?

- The very sign of the delta came to us from the Greek language. This is one of the letters of his alphabet.
- To date, scientists believe that it served as the progenitor of the Latin letter D, which is present in most of the alphabets of European countries and not only.
- A large symbol of this letter is an isosceles triangle, with the smallest side (that is, “Δ”) at its base.
- In turn, the capital letter is a small circle with a characteristic upper tail (it looks like this: “δ”). A little later these symbols began to be actively used in various spheres of human life, among which one particularly can distinguish mathematics and geography.

### Delta symbol in geography

This concept is widely used in geography. Here, by this term, the region of confluence of the river into the sea or ocean is hidden. From above it looks like a triangle. That is, the analogy here is obvious, and such a definition in this case is more than justified.

The most striking examples are the Nile River (it flows into the Mediterranean Sea in the northern part of the African continent) or the Amazon (it flows into the Atlantic Ocean and is located in South America). From a bird’s eye view, the places at the junction of land and water of these two great rivers really look like the Greek letter Δ.

### Delta symbol in mathematics

A **delta symbol** is more often used in mathematics. Here it can denote the following:

- Increment of arguments. That is, behind this concept lies the value to which the variable has changed. For example, 2 + 3 = 5. In this case, 2 is increased by 3. This is Δ.
- Another case in which this letter of the Greek alphabet is used is the Laplace operator.
- The last variant, in which Δ is used, is the designation of the determinant of the matrix.

### Where else is the delta symbol used?

Another sphere where this Greek letter is universally used is physics. Most of the values of this science are related to each other in the form of integrals and derivatives. For example, the speed is the ratio of δS to δt, that is, the distance traveled to the time for which it is overcome. In turn, the second-order derivative of the velocity over time will be the acceleration. This is just one example, which shows how important this Greek letter is for modern physics.

Greek δ has no less significance for astronomy and cosmology. Here again, many quantities are interrelated by means of integrals and derivatives. It is the latter concept and is denoted by a capital letter delta.

In conclusion, it should be noted that, despite its venerable age, the **delta symbol** has not lost its relevance and is widely used in many modern sciences.