To read this post, you have to be familiar with basic Express, Mongoose and solid Javascript background. Libraries I’ve used in this example: Express: web framework Mongoose: modeling User object…

## Integration formula

An integral is the area under a function’s curve. Take a look at this image: The area of the darker colored section is called the integral of f(x) in the…

## Limits Of Functions

a limit is the value that a function approaches some value. In formulas, a limit is usually written as and is read as “the limit of f of x as x approaches a equals L”. Rules for Limits:…

## Secant and Tangent Lines

A secant line is a straight line joining two points on a function. It is also equivalent to the average rate of change, or simply the slope between two points. A tangent line is a straight line…

## Derivative: definition and rules

The derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value)….

## Trigonometric formula

Trigonometry is a branch of mathematics that studies relationships involving lengths and angles of triangles (Wikipedia). There are six main trigonometric functions: Sine (sin) Cosine (cos) Tangent (tan) Secant (sec) Cosecant (csc) Cotangent (cot) Trigonometric formula…

## Logarithm formula

The Logarithm is the inverse function to exponentiation. That means the logarithm of a given number x is the exponent to which another fixed number, the base b, must be…

## Add update icon to WordPress Plugin

In this post I’ll demonstrate how you can add update icon to your WordPress Plugin. If you don’t host your plugin on WordPress.org. When it has a new update, you…

## Safest way when using for .. in to loop through an array or object in Javascript

There are so many ways to loop through an array or object in Javascript, one of them is using for .. in. For example:

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var arr = ['David', 'John', 'Tom', 'Peter']; for ( var i in arr ) { console.log( arr[i] ); } /* Output: David John Tom Peter */ |

It looks correct, right? But…

## 7listings – WordPress Theme that makes you money

Do you want to build a professional website for your hotel with no trouble at all? Are you trying to find the best touring and traveling theme for WordPress? 7listings…