# Quick Guide To LaTeX (part-2)

Updated: Jun 13, 2019

## In previous part of Quick Guide To LaTeX

What is Latex, how to set your document and some basic functions of mathematics.

## In this part

some environment (for math) of laTeX like equation array, equation;

some mathematical functions like differentiation, integration, Summation etc

__Equation Array__

__Equation Array__

consider that we are writing some mathematical derivation, in which we are supposed to write a series of equations. In this case using Dollar sign again and again will be tedious. Hence in LaTeX we use a function called Equation Array. To use this function we use code \begin{eqnarray}. At the end you have to write end{eqnarray}, otherwise code will not compile

In the above image you can see for both equations, a number has been assigned by the program. But second equation has shifted slightly to the left. to solve this problem we can use "&" (And sign) at both sides of "=" (Equality). This will align all equality sign.

__Limits__

__Limits__

In math we deal with Limits every now and then. In LaTeX to write limit of function we use a simple code.

Suppose we want to use limit of a function 'f(x)' from 'x' to 'infinity

We can use code

\ref{limit} Write this command before writing any Limit

\lim_{x \to \infty} f(x) This is the code for limit of f(x) from 'x' to 'infinity

Using similar code you can write different limits of different functions.

**Note:-** Code for infinity is infty

__Summation__

__Summation__

Suppose we want do a summation of 'X^2' from x = 1 to x = n.

In LaTeX we can write the code for above function as

\ref{sum} Write this command before writing any Summation

\sum_{x=1}^{n} x^2 This is the code for Summation of 'x^__2__' from x = 1 to x = n.

In above code instead of using **Equation array** environment I have used environment **Equation**, because I have only one equation.

**Differentiation**

**Differentiation**

Differentiation is one of the most important function in mathematics. There are many ways in which we write a derivative such as f'(x), df/dx, partial differentiation etc.

\ref{derivative} Write this command before writing any derivative

\frac{df}{dx} This type of code to write in the form df/dx

\frac{\partial f}{\partial x} This code is for Partial Derivative

f'(x) This code is for First order derivative

f''(x) This code is for Second order derivative

**Note**:- You can use \ref{partialder} for partial derivative.

__Integration__

__Integration__

Similar to differentiation, Integration is also one of the most frequently is used Function in mathematics.

In integration we deal with Indefinite and definite integration. We can write these symbols in LaTeX easily

\ref{int} Write this command before writing any integration

\int xdx For Indefinite Integration

\int_{0}^2 xdx For definite Integration

If you find any difficulty about writing any above mentioned function please contact me on my email **prabhanjan1804@gmail.com**

Also if you need me to explain any other function of LaTeX please let me know in comments.

Thank you & happy TeXing....