# Hot Education Posts  ### How To: Find a slope of a straight line with: Ax + By + C = 0

In this video the instructor shows how to find the slope of an equation which is in the form Ax + By + C = 0. He says that the formula to find the slope of a line in the above form is slope m = -A/B, where A and B are the numeric constants of the variables x and y in the given equation. He goes on and further shows how to do this with a couple of examples. He shows how to reduce any equation into the general form and how to apply the slope formula then. This video shows how to find the slope ... ### How To: Solve equations with the order of operations

In mathematics, the order of operations define the priority in which complex equations are solved. The top priority is your parenthesis, then exponents, followed by multiplication and division, and finally addition and subtraction (PEMDAS). This video tutorial demonstrates the order of operation with various examples and explains the associated methodology. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autod... ### Make Slime Without Borax: 5 Easy Recipes for Gooey Homemade Ooze

One of the only things I remember from watching Nickelodeon as a kid is the epic green slime. Looking back, I don't know what was so great about it, but every kid my age thought that being drenched in slime would be the coolest thing on earth. ### How To: Calculate percent error in chemistry lab activities

If you want to know how to calculate percent error easily, you should watch this video. Error is the amount of deviation from accurate values. Error calculation is not possible, unless you make a quantitative measurement of the various quantities involved in your experiment. Measurement can help us in calculating errors and knowing how right we are in our theoretical models. In calculating percent error, We need to get the experimental value and the value which you are aiming at, which is the... ### How To: Recognize and analyze iambic pentameter

Meter, specifically iambic pentameter, can be used to analyze a poem. Iambic pentameter is used in poetry and drama and describes a particular rhythm that words establish in each line. Rhythm is created through the stressing and un-stressing of syllables. Small groups of syllables are called feet. A foot is a group of two or three syllables and will often contain a stressed and an unstressed syllable. Iambic describes the type of foot that is used. Pentameter indicates that a line of poetry h... ### How To: Calculate circular velocity & acceleration

In this video the tutors explain about the concepts of Circular Velocity and Acceleration. She explains the concepts using a real world small experiments. She shows that the equation to calculate circular velocity is v = (2 * Pi * r) / T, where r is the radius of the circle the object moves in, and T being its time period. Now she takes the values from the experiment and calculates the velocity of the other tutor who is the object that runs around in the circle for the experiment. She even co... ### How To: Use a Peltier module to create free electricity from heat

A Peltier module allows you to turn heat into electricity. Because you can place it in areas that are normally warm anyway, the electricity created is "free" in a sense, though it does work best when one side of the module is cold and the other is hot. In other words, all you'll need for this project is the Peltier module and a cooler surface such as soil or water, and a warm area such as a well lit window or warm pan. ### How To: Find the x & y intercepts of rational functions

In this tutorial the instructor shows how to find the x and y intercepts of rational functions. Finding the intercepts of a rational function is similar to finding the intercepts of other normal equations. You can find the x intercept of the equation by setting the value of y to zero and solving the equation. Similarly you can solve the y intercept by setting the value of x to zero and solving the equation. Now while solving this rational function for intercepts if you face a situation where ... ### How To: Isolate the sugar in a can of soda

In this video from ScienceOnTheBrain we learn how to isolate the sugar in a can of soda. To find out how much sugar is in soda, pour a can into a pot and boil it until all the water is gone. You will be left with the sugar, and then you can weigh it. First weigh your pot before pouring the soda in. Now boil the soda on the stovetop. When the water evaporates, you'll be left with a syrupy sugar. A can of soda has 39 grams of sugar in it. That equates to about 7 1/2 teaspoons. Fruit juice conta... ### How To: Write a sum/difference of logarithms as a logarithm

To write the sum or difference of logarithms as a single logarithm, you will need to learn a few rules. The rules are ln AB = ln A + ln B. This is the addition rule. The multiplication rule of logarithm states that ln A/b = ln A - ln B. The third rule of logarithms that deals with exponents states that ln (M power r) = r * ln M. Using these three rules you can simplify any expression that involves logarithms to arrive at a single logarithm. The instructor shows how to apply these rules to a f... ### How To: Use superglue to reveal latent fingerprints

Do you need to check a scene for prints, or are maybe just curious about the techniques of forensic science? In this video, Robert Bruce Thompson from the Home Scientist unravels the mysterious of forensic fingerprinting using common materials that you may already have sitting around in your home right now. Explains and demonstrates the process of superglue fuming step-by-step to reveal latent fingerprints. Includes great tips on how to improve and speed up the process using household products. ### How To: Simplify a quadratic formula result

In this video the tutor shows how to simplify a quadratic formula result. You can solve a quadratic equation using the quadratic formula. The first thing you have to do when given the quadratic equation is bring all the terms to one side so that you have a zero on the other side of the equals to sign. Now the formula to calculate the roots of the quadratic equation ax*x + bx + c = 0 is x = (-b + root of(b*b - 4*a*c) ) / 2 * a. The other root can be obtained by using the minus sign before the ... ### How To: Use baby powder to reveal latent fingerprints

This short video shows us how to reveal latent fingerprints on a glass surface by dusting. Anyone interested in forensic science would enjoy trying it as it shows simple steps in dusting and lifting fingerprints. It does not require any chemicals and we can do it with baby powder. The steps involved are so simple and easy to follow that even kids can try it out for fun. This gives a clear idea about fingerprints on different objects like porous, non porous and metals. Enjoy viewing and detect... ### How To: Find a missing coordinate given: coordinate & equation

In this video, the instructor shows how to find an unknown coordinate given the other coordinate of that point and the equation that passes thought the point. A point is said to lie on the graph, if the point can satisfy that equation of the line. To check if a particular point satisfies an equation, all you have to do is substitute the value of the point in that equation and check if it validates the equation. Now, substitute the given point with an unknown coordinate in that equation. If th... ### How To: Prove Rank(A) = Rank(transpose of A) in linear algebra

Learn how to prove that the rank of a matrix, A, is equal to the rank of its transpose in linear algebra. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). ### How To: Make green fire from household materials

In this video, we learn how to make green fire from household materials. You will need: antifreeze, boric acid, and a glass jar. First, pour the antifreeze into the jar until it's 1/3 of the way filled. After this, drop a spoonful of the boric acid into the mixture and mix it up thoroughly. Now, let it sit for 30 seconds and then go into a dark room. Light this up, then watch it burn! You can also put it into a spray bottle and spray it over a flame to see the green fire right in front of you! ### How To: Make your own thin-layer chromatography (TLC) plates

The price of TLC plates can add up. See how to make thin-layer chromatography plates (TLC plates) for a few cents each that are as good as commercial TLC plates that sell for a dollar or two each. You can use these home-made TLC plates the same way you'd use chromatography paper, but the plates provide sharper separations and require far less analyte. They also lie flat, and are much easier to store for later reference. For more information, including step-by-step instructions, and to get sta... Glow sticks, a popular favor at parties and outdoor events, and a must-have on Halloween, can be traced back to the United States Navy in the mid-1960s. The military desired improved visibility during night operations, and glow sticks, with their small-size portability and lack of batteries, were a perfect tactical solution. ### How To: Do long division without a calculator

This video shows you step by step how to do long division without the use of a calculator. The video shows viewers two different ways to solve a division problem. It first shows how to do the problem the traditional way, then it shows how to do it according to the long division process. The long division process is where you write the whole division, multiplication, and subtraction process out showing all your work. Long division is mainly used when dividing large numbers. There are three com... ### How To: Remember "greater than" & "less than" symbols

This video shows you how to easily remember "greater than" and "less than" math symbols. The first thing you have to remember is that "less than" symbol looks like the letter L ("less than" symbol is "<"). When you see this sign, remember that < looks like L and means "less than". The other symbol, "greater than" does not look like the letter L, therefore it cannot be "less than" and it's easier to remember. The "greater than" symbol is ">". That's it! Good Luck! ### How To: Figure out the domain & range of a piecewise function

Need to calculate the domain and range of a graphed piecewise function? Learn how with this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). ### How To: Prove a triangle inscribed in a circle is right angled

When a triangle is inserted in a circle in such a way that one of the side of the triangle is diameter of the circle then the triangle is right triangle. To prove this first draw the figure of a circle. Now draw a diameter to it. It can be any line passing through the center of the circle and touching the sides of it. Now making this as the side of a triangle draw two lines from the ends of the diameter to a point on the circle. Now join the center of the circle to the other vertex of the cir... ### How To: Find extra points for a parabola (quadractic equation)

This is a mathematical educational video on how to find extra points for a parabola. In the first two examples there is no need for finding extra points as they have five points and have zeros of the parabola. In example 3 we need to find extra points. The equation is y=4xsquare-4x+4. You can take x= -1 and get the value for y. You will get a point now. Similarly you can substitute -2 for x in the same equation and get the value for y. Now you get another point. Now you can draw the parabola. ### How To: Find the equation for a growth pattern

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find an equation that describse the growth pattern of a sequence of blocks. ### How To: Complete a proof involving segments

This video from Yay Math! is a geometry lesson on how to complete a proof involving segments. He draws a line segment with four points labeled A, B, C and D. The problem is as follows: Given: AC is equivalent to BD. Prove that AB is equivalent to CD. The first statement of proof is the given. Next, you need to define the congruent segments and state that they're equal in measurement. Next, break down the segments: AC=AB+BC, and BD=BC+CD. This is called segment addition postulate. The end of t... ### How To: Make Potassium Chlorate from Ordinary Household Bleach and Salt Substitute

If you're not just a chemistry nerd, but also a firearms freak and explosives nut, then this home brew chemistry concoction is just what you need for some cheap homemade potassium chlorate. It's a mixture of potassium, chlorine and oxygen (KClO3) and is used for such things as gun primers, propellents, and explosives (when mixed with the appropriate fuel). And guess what? NurdRage is going to show you the steps for this makeshift potassium chlorate. ### How To: Cancel out in basic algebra

This video gives you brief tutorial on simplifying expressions, or canceling out common factors. He starts out by answering the question "What is canceling?" and demonstrates a basic example. You find the greatest common factor between the numerator and denominator, which you then divide both by. This can also be done if you have variables in your fraction. He then shows it can be done the same way if you have binomials in your fractions. However, you must be careful that the denominator does... ### How To: Get your official SAT score from College Board online

The SATs are a very valuable college entrance test and could determine if you're accepted or denied to your favorite university. So, once you've learned to ace the SATs and have already taken your test, get your scores as soon as they're out! Don't sit in dreaded anticipation— go to College Board and get your SAT test results now! ### How To: Find the circumference of a circle

Use a simple mathematical formula to find the circumference of a circle. The circumference of a circle can be determined by using the formula 2 times pi times the circle's radius. Pi is equal to 3.14. If a circle's radius is 10 centimeters, first multiply pi times 2. Pi, or 3.14, times 2 is 6.28. The next step then is to multiply 6.28 times the circle's radius. Since the circle's radius is 10 centimeters, multiply it by 6.28. This gives you 60.28. 60.28 inches, then, is the circumference of t... ### How To: Know if matrices can be multiplied

In this Education video tutorial you will learn how to know if matrices can be multiplied. If the column of the first and the row of the second match, you can multiply them. For example if, matrix A has 2 rows and 3 columns (A: 2x3) and matrix B has 3 rows and 4 columns (B: 3x4), then you can multiply them. But, if A: 3x2 and B: 3x4, you cannot multiply them. The shape of the resultant matrix will be the shape of the outer numbers. For example, we saw that if A:2x3 and B :3x2, then they can b... ### How to Be Your Own SpaceX: Design, Build & Test Liquid-Fueled Rocket Engines

Move over NASA— SpaceX is taking over. Well, not really. But today, the privately funded spacecraft company broke all expectations when their Dragon capsule fell to a soft landing in the Pacific Ocean, completing an undoubtedly successful demo flight of nearly two full trips around Earth. It was the first re-entry of a commercial spacecraft ever, bringing commercial space transportation closer to reality. ### How To: Figure out the domain of a vector function

Need to know how to calculate the domain of a vector-valued function? Learn how with this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). ### How To: Multiply rational expressions with opposite signs

In this video the instructor shows how to multiply and write rational expressions in lowest terms. The fist thing you need to do is cancel out the common factors in the numerator and the denominator. You can cancel a term in the top with a term in the bottom even if they are diagonal as long as one is in numerator and the other is in the denominator. After cancellation if you have a term in numerator and an identical term in the denominator but with opposite signs, then pull out the negative ... ### How To: Solve direct proportions

You can solve any proportion using the fundamental rule of proportions. First you must build the proportion if you are given a word problem. Decide using logic whether it is a direct proportion (more on one side means more on the other). If so, find the parts of the equation that use the same units and make a fraction with these, putting the smaller number on top. The number left over is linked with one of the other two numbers in the fraction--use logic to figure out which. Put it in the sam...