## Calculus in Physics:

Calculus is a very important branch of mathematics. In the branch, the main pillar is the magnitude and multitude of infinitesimal numbers. There is no better tool in mathematics than calculus to express any physical quantity in mathematical terms.

Calculus is a Latin word that means ‘small pebble that is used in an abacus for counting counting’. The word calculus is also used in Latin as a synonym for counting.

__Application of Calculus:__

**1. Variable and constant:** A variable is a value that may change within the scope of the given problem or set of operations. A constant is a value that remains unchanged.

**2. Real variable and complex variable:** The value of a real variable is real and that of a complex variable is complex. Any complex variable has two parts:

**i. Real part:** Suppose zx+iy is a complex variable, here, x is the real part.

**ii. Imaginary part:** Suppose zx+iy is a complex variable, here, y (or iy) is the Imaginary part.

**3. Function: Independent variable and dependent variable:** Any function relates two-variable or variable quantities. Of these, one is a dependent variable, and the other is an independent variable.