To solve a proportion for a variable you should employ cross multiplication. The basis of cross multiplication is the property which states that the product of the numerator of one fraction and the denominator of what it is set equal to is equal to the product of the remaining denominator and numerator. For example if you have x/15=21/45 you simply need to multiply x by 45 and 15 by 21 then set them equal to each other. The result of this is 45x=315. To solve this new problem for x, divide bo...
This video shows the method to solve word problems using proportions. In the given problem, we have to find the time taken by a person to type 390 words if the person takes 1 minute to type 30 words. This can be solved using proportions. We take two fractions which are equal. We type '30 words' in the numerator of the first fraction and 1 minute in its denominator. This fraction must be proportional to the second fraction. The second fraction has '390 words' in the numerator and the variable ...
Welcome to Google's Python Class – a seven-segment, two-part free virtual class for people with a little bit of programming experience who want to learn Python. The class includes written materials, lecture videos, and lots of code exercises to practice Python coding. The first exercises work on basic Python concepts like strings and lists, building up to the later exercises which are full programs dealing with text files, processes, and http connections. The class is geared for people who ha...
All you science and astronomy nuts out there, pay attention, this detailed video tutorial series will tell you everything you need to know about using the Meade EXT Backpack Telescope to ogle the universe.
All you science and astronomy nuts out there, pay attention, this detailed video tutorial series will tell you everything you need to know about using the Meade ETX-AT Series Telescope to ogle the universe.
For some odd reason, the Netflix app likes to disable the Nexus Player's built-in screensaver. It doesn't use its own, it simply keeps your screen on indefinitely, which of course can lead to screen burn-in. This is not just an Android TV issue, as the Netflix app does the same thing on Roku and smart TVs.
Being able to write your own hacking tools is what separates the script kiddies from the legendary hackers. While this can take many forms, one of the most coveted skills in hacking is the ability to dig through the binary files of a program and identify vulnerabilities at the lowest level. This is referred to as binary exploitation, and today we're going to check out a tool known as Protostar.
Love Microsoft Excel? This clip contains a tip that just might induce you to. With this free video tutorial from ExcelIsFun, the 51st installment of his "YouTubers Love Excel" or YTLE series of free video MS Excel lessons, you'll learn how to use a VLOOKUP function inside a Text Formula to add a variable word (e.g., Annual, Semi-Annual, Quarterly, Monthly, or Weekly).
Chest hooping is no more complicated than spinning at the waist, and has a great variety of movement possibilities because of the variable choices of arm and shoulder placement. Safire, expert hula hoop dancer, walks through the simple steps of doing this stunt, breaking down each movement to exact body positions and also thoroughly explaining any of the hula hoop choreography terminology she uses. Watch this video hula hoop tutorial and learn how to rotate a hula hoop at chest level.
Hello null_byters, after some time out here we are again with another tutorial, continuing our beautiful series, today we will write our first real world bash script.
Want to learn how to do quick scoping in BO? It's easy: use the variable scope and zoom in to the second or third level of magnification. Voilà. No more two-second delay when shooting. For a complete walkthrough of how to quick scope, watch this gamer's guide.
The powers of the complex number "i" run their course in a cyclical nature, like annual seasons of "American Idol." Simplify your life - or at least your math class life - by learning how to rewrite the powers of "i" into simple, single variable expressions.
This series on complex numbers will help you solve equations with the cute variable "i" with ease by multiplying by the conjugate.
Welcome back, my amateur hackers! Over the course of the next year, we will be developing our own zero-day exploits. In my first article in this series, I introduced you to buffer overflows, which are the source of some of the most lethal exploits, particularly the "remote code execution," so we are focusing our exploit development here on a buffer overflow.
In this Education video tutorial you will learn how to solve a word problem that involves proportions. To solve such problems you got to express the scenario in proportions. For example, in the problem, ‘Jacob ran 10 miles in 80 minutes’; this rate can be expressed as 10miles/ 80 minutes. The second part of the problem is to find out ‘at that rate how far would he run in 2.5 hours’? ‘How far’ being a variable, write it as ‘x’ and this can be expressed as x/ 2.5 hours. So, the complete equatio...
In this video the instructor shows how to solve a quadratic equation. If you have a quadratic equation with complex fractional terms and you find that a particular term is repeating then equate that term to a new variable and replace the variable in the given equation. Now try to get the equation a*x*x + b*x + c = 0, and solve for the roots of the equation which gives the values of the intermediate variable. But this variable was replaced instead of another term. So equate that term to the va...
Developers creating login systems know better than to store passwords in plain text, usually storing hashes of a password to prevent storing the credentials in a way a hacker could steal. Due to the way hashes work, not all are created equal. Some are more vulnerable than others, and a little Python could be used to brute-force any weak hashes to get the passwords they were created from.
During our last adventure into the realm of format string exploitation, we learned how we can manipulate format specifiers to rewrite a program's memory with an arbitrary value. While that's all well and good, arbitrary values are boring. We want to gain full control over the values we write, and today we are going to learn how to do just that.
After a long hiatus, we shall once again emerge from the shadowy depths of the internet to build an exploit. This time, we'll be looking at how to defeat a non-executable stack by using the ret2libc technique — a lean, mean, and brilliant way of exploiting a stack overflow vulnerability.
Welcome back Java programmers! In this tutorial we'll being going over Variables/DataTypes and Type-casting
In this video the instructor shows how to find a formula describing direct variation between two variables. Variation between two variables can be either direct variation or indirect variation. If a variable y is in direct variation with a variable x we can write the general equation between them as y = k * x. That is as x varies, y varies directly in relation to x, as a multiple of x. Now if you have the values of y and x, you can substitute them in this general equation which gives you the ...
In previous tutorials we have encountered these things called pointers and addresses but we still don't know what they really are. Let's learn a bit more to clear things up.
Last time in how to train you python, we covered the basics of variables and output. While we were covering variables, we talked briefly about strings. "String" is just a fancier way of saying "Word". A string is simply a set of characters encased in quotations, this lets python know that it is a word. Sometimes when we do things with strings we'll need to change them in order to do something. Python is case sensitive, for example "Null-Byte" is not the same as "null-byte". This is where mani...
Hey readers! This tutorial will be the entry point for the introduction of buffer overflows. Something like requesting user input is a very common place for vulnerabilities to pop up and we will definitely have fun while trying to make programs crash. But for now, let's start with how we can get input from a user.
NOTICE: Ciuffy will be answering questions related to my articles on my behalf as I am very busy. Hope You Have Fun !!!
What's up readers? We have ever so slightly touched upon this concept of scope with variables but still don't really know what it means. In this tutorial we will learn the behaviors of variables existing in our programs and within functions.
All the files you need are in a free download on DevelopPHP. PHP has to be on a server. It will not run on a local machine. Type your name. There are two variables which show up in the dialog boxes (which are stacked.) You can change the user name. It sets up a URL request and a URL loader and sends some URL variables and are placed into the value of names and pairs. They get posted to the PHP file. Place the URL reference location of where the PHP files are on your server in the line that sa...
This video teaches you how to use substitution to find the point on a graph (the x and y coordinates) where two separate equations would cross. Substitution is a trick of algebra that allows you to find this point without making a graph. The first step is to isolate one of the variables (x or y) in one of the equations. That way, you know that that variable is equal to everything on the other side of the equals sign from it. You can then take that whole side, and substitute it into the other ...
Math can be tricky, especially when you're trying to decipher algebra. It's a love-hate thing; if you don't love math, then you hate it, and there's no in-between. But it doesn't have to be a pain to solve a few problems. It's actually quite simple once you figure it out. An algebraic equation is an equation that includes one or more variables. These equations can be solved as long as the number of variables does not exceed the number of equations.
Learn how to do two step math problems with this video tutorial.
In this tutorial the instructor discusses about the numeric coefficients that we come across while we work with polynomials. He goes on to discuss the numerical coefficient of a monomial stating that it is the number that is present before the variable in the monomial. He states that the numerical coefficient can also be negative or if there is no number present in front of the variable, it indicates that the numerical coefficient is one. This video helps in understanding what the numerical c...
In this video tutorial the instructor shows how to solve equations by the comparison method. In this method he isolates either the x or y variables in both the equations and now compares the other side of equations directly to derive the value of the other variable. Now this derived value of the variable can be used by substituting it in one of the original variables to derive the value of the other variable. He goes on and shows how to do this with an example by solving it. This video gives ...
Welcome back, my fledgling hackers! In an earlier tutorial, I introduced you to probably the most popular scripting language for hackers, Python. To become a professional hacker, you need to have some scripting skills and Python is a good choice if you want to master just one. In this latest guide, I will expand your background in Python and offer you a tidbit of Python code to whet your appetite for all of the hacking to come.
What's up readers? Today I'll be introducing to you a new vulnerability called the Format String vulnerability (in case you missed the title). It won't be much, just a little motivation to keep you guys going. A little teaser, if you may.
This video demonstrates how to solve algebraic equations of the first degree for the variable, "X"; in other words, the variables contained in these equations are not raised to any power other than one, which is implicit. The video starts out with an example of such an algebraic equation. Before beginning to solve the equation, the video explains the meaning of the equals sign, the definition of an equation, and what a variable is. Next the video explains what is meaning by "solving for X". T...
This video demonstrates the quotient rule as applied to exponential expressions that appear in the form of, to use the word loosely, a fraction. The name, "quotient rule", refers to the fact that it applies to expressions which are divided by other expressions. The video begins by explaining that the quotient rule allows expressions in this form to be simplified if they contain like bases (i.e., the terms are of the same variable). The quotient rule allows the expression to be simplified by s...
Create drums sounds using Reason's Thor synthesizerYou can use the Thor synthesizer to make a kick, snare, hat and clap sound.Kick:Use the analog oscillator with triple wave form octave3. Set the source to mod envelope 45 destination oscillator 1.Use a very short attack to K and release time. You get the short effect of pitch. Try different oscillator types to get different textures.Snare: Use the same basic patch that we created for the kick. We will keep it as the basis for most patches for...
Why did I write this when they're tons of scanning tools available.
Welcome back, my greenhorn hackers! Recently, I asked the Null Byte community what subject they would most like me to cover in future tutorials. Many of you cited scripting, and I decided it's best to cover this subject soon, so here goes.
Solving Equations with Fractions Using Addition In our first example, our equation is b - 11/10 = -13/5
