Hot Education Posts

How To: Determine the empirical and molecular formulas for a compound in chemistry

In this free video science lesson from Internet pedagogical superstar Salman Khan, you'll learn how to determine the empircal and molecular formulas of a substance given percent composition. Whether you need help studying for that next big test or could just use a hand finishing your homework, you're sure to be well served by this video lesson. For more information, including detailed, step-by-step instructions, take a look.

How To: Multiply & Divide Numbers (Basic Elementary Math)

Adding and subtracting may be the easiest of mathematical operations, but once you get it down, multiplication and division can be just as easy. That's why it's called elementary arithmetic. If it were harder, it would be called college algebra or trigonometry. But it's not— it's basic math, and once you get your head around the numbers, you'll never hate math class again! (Okay, maybe you will.)

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: Make boric acid from borax

This is a video tutorial in the Education category where you are going to learn how to make boric acid from borax. For this experiment you will need borax (disodium tetra borate) and conc. hydrochloric acid. Take 25 ml of hydrochloric acid and dilute it with 75 ml of water. Next take 6 - 7 gms of borax and dissolve it in boiling water. Now add equal amount of hydrochloric acid. Crystals of boric acid will start forming. They are completely insoluble in cold water. After about half an hour, fi...

How To: Solve word problems involving direct variation

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 solve word problems involving direct variation.

How To: Solve a word problem that involves proportions

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...

How To: Find the equation of a line given 2 points

This tutorial teaches you how to find a mathematical equation of a line given 2 points that exists on the line. The tutorial starts off with 2 points labeled (2,-4) and (3,6). The first step is to determine the slope of the line using the formula given in the tutorial in blue. The slope is then solved as 'm'. Plug the slope and the points into another formula given in green. The tutorial maker provides a tip that one can use x1 and y1 or x2 and y2, however, it must be consistent. After, solve...

How To: Find the perimeter & area of a complex figure

In this video tutorial the author shows how to find the perimeter and area of a complex figure. He shows that a complex figure can be subdivided into standard geometric figures. In the current example he divides the complex figure into a rectangle and a triangle. Now he computes the perimeter by adding the three sides of the rectangle and the two sides of the triangle. Similarly he computes the individual areas of the rectangle and the triangle and finally adds then up to find the area of the...

How To: Find the vertical asymptotes of rational functions

To find a vertical asymptote, you are trying to find values of x that produce 0 in the denominator but not in the numerator. If 0/0 occurs, that means you have a "hole" in the graph. A vertical asymptote is a place in the graph of infinite discontinuity, where the graph spikes off to positive or negative infinity. To find the vertical asymptote, set the denominator equal to zero and solve for x. Check that the values also do not give a zero in the nominator. If the values work, you have found...

Do Not Try This At Home: The Human Torch

PopSci's Gray Matter demonstrates again and again what the layman should absolutely Not Try at Home. Which is precisely what makes Gray's experiments so fun. Remember when the mad scientist fully submerged his hand in liquid nitrogen? Today's demonstration also plays with what is (quite reasonably) assumed to be extremely dangerous and painful: torching the human hand.

How To: Explore Density, Viscosity & Miscibility with a Colorful Layered Liquid Science Experiment

Ever wonder why Jupiter has those colored bands across its surface? Jupiter's enormous mass is made from an array of different liquids, and those fluids do not play well together because of their different makeup. All of the hydrogen- and helium-based fluids are thought not to be miscible, which means that they aren't homogeneous in nature, resulting in strikingly beautiful bands across the planet's surface. But what about viscosity and how that correlates to the development of planets? What ...

How To: Find the standard deviation with the Z-Score formula

In this tutorial, we learn how to find the standard deviation with the Z-Score formula. First, take your problem and write it out one by one underneath each other. Then, you will need to substitute the numbers in for the variables that are in the problem. Once you do this, you will follow the basic rules of math to find out what the answer to the problem is appropriately. Once you have done this, finish off the problem to find the answer, then you will have found the standard deviation using ...

How To: Write A Letter From Teachers To Parents

Parental involvement is a crucial ingredient in the success of many children. Teachers know the saying all too well that it takes more than a village to raise a child, for one - it takes parental involvement. Thus, it is important for teachers to reach out to parents in that first week of school. Teachers should write a formal letter that is welcoming and easily comprehensible to the parent and the student. This letter should be able to communicate that the teacher values the child’s educatio...

How To: Add fractions with unlike denominators

In order to add fractions that are not alike, you will need to find the lowest common denominator. This is the least common multiple of the fractions. To add 2/3 plus 1/5, you will need to find the lowest common denominator. Here, it is best to think of all of the multiples of the denominators. If it helps, make a list. For 3, it is 3, 6, 9, 12, 15, etc. For five, the multiples are 5, 15, 20, 25, etc.

How To: Solve word problems involving domain and range

See how to find the domain and range of a function implied by a word problem with this free video math 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). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutor...

How To: Find the 100th term in a sequence

Need to find the nth term in a given arithmetic sequence? See how it's done with this free video math lesson. Need help finding the 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 seri...

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: Add and subtract rational expressions in algebra

In this math tutorial, you'll be trained in the arcane art of adding and subtracting rational expressions by finding the common denominator. A skill many discard upon leaving middle school, it is used by the villians who operate under the acronym "SAT" to test those caught blank minded and whose minds are unrationalized.

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...