Mathematics Archives - Page 4 of 5

28Nov 2014 by Vincent Summers 3 Comments

Most Efficient Shape for Holding Liquids

[caption id="attachment_6496" align="alignright" width="440"] Spherical Bottle.[/caption] We store liquids in a bottle. So what is the most efficient shape that uses the least glass to store the most liquid? The volume of a sphere divided by its surface area represents the greatest ratio possible of any geometrical object. We want to use the least material to construct the vessel, while it holds the most. How shall we determine what best meets our requirements? Most Efficient Shape We determine what best meets our requirements by logic supported by mathematics. V/S (sphere) = 4/3пr3/4пr2 = r/3 Use, for purposes of comparison and illustration, a cube, whose dimensions are "a" on a side. Then, since its surface area is the area of its six sides, V/S (cube) = a3/6a2 = a/6 Now since…

17Nov 2014 by Vincent Summers No Comments

Introduction to Polar Coordinates

Mathematics

[caption id="attachment_25281" align="alignright" width="403"] Polar rose: r = 2 sin (4*θ)[/caption]Frequently used in analytical geometry is the standard 2-dimensional x, y coordinate system called the Cartesian coordinate system (named after famous mathematician, René Descartes). It's time to branch out to a different system, the polar coordinates system. In fact, there are any of a number of ways of locating points in 2-D space. Conversion from Cartesian Coordinates The polar coordinates system utilizes an angle and a radius. It is relatively simple to change from the x-y system to an r-θ system. Drawing a circle centered at the origin on an x-y plane and then drawing a right triangle with the radius of the circle equaling r, then by definition, the side adjacent to the angle divided by the hypotenuse (longest…

15Nov 2014 by Vincent Summers No Comments

Analytic Geometry: The Parabola

Mathematics

What is a parabola, and of what use is it? If a sheet of paper is likened to an infinite plane in space, the x- and y-axes, drawn at right angles to each other, provide a means of describing each point on the plane of the paper in terms of an x and a y value. Thus the point (1, 3) tells us that beginning at the origin or center where the x-axis crosses the y-axis, if we travel one unit to the right and then three units up, we will have reached the point we seek. Introducing the Parabola Now we will pass on to describing a parabola.1 The parabola is an important mathematical "curve," inasmuch as it describes, mathematically, the behavior of a number of important actions, such…

15Nov 2014 by Vincent Summers No Comments

Analytic Geometry: The Hyperbola

Mathematics

[caption id="attachment_6399" align="alignright" width="380"] Simple hyperbola with asymptotes. Image by author.[/caption] The parabola, ellipse, circle, and hyperbola are all termed conic sections. This means that a plane that cuts into a cone in just the right way will generate one of these figures. We will consider the basic equation of a hyperbola and graph one. Equation of an Hyperbola It may be recalled the equation for an ellipse centered at the origin is, x2/a2 + y2/b2 = 1 where 2a is the length of the ellipse and 2b is its height. The equation for an hyperbola centered at the origin is very similar, x2/a2 - y2/b2 = 1 The graph of this function is completely different from that of an ellipse. Let's look at a very basic one, for which…

14Nov 2014 by Vincent Summers No Comments

Introduction to Cylindrical Coordinates

Mathematics

What are cylindrical coordinates? A coordinate system is a system that provides a way to describe points and other features of geometric figures in Euclidean space. Generally the best coordinate system is that system which adequately does the job in simplest fashion. In this article, we will use (r, Φ, z) for our new coordinate system. Many use this, but others use a different assortment of letters, unfortunately. Forewarned is forearmed. Cylindrical Coordinates - Introspection When we're working in two dimension, we are able to draw our coordinate axes using the sheet of the paper, representing a plane. Two orthogonal axes are drawn, one horizontal the other vertical. When using r and Φ the way we view the axes is really different from how we view them when they represent x…

03Nov 2014 by Vincent Summers No Comments

Analytic Geometry Coordinate Axes and Drawing a Line

Mathematics

In analytical geometry (usually taught in high school), two lines are drawn on a paper that are perpendicular to each other. The vertical line represents the "y-axis," and the horizontal line represents the "x-axis." Using these two axes, every point on the paper can be given a value that defines where the point is. If the place where the two lines cross is the zero point or origin, its coordinates (x, y) are simply, (0, 0). Along the horizontal x-axis, starting to the right of the (0, 0) point, write little numbers like a ruler has, 1, 2, 3, and so forth. To the left of that point, write, -1, -2, -3, and so on. For the y-axis, the 1, 2, 3, and such go upward, whereas the -1, -2,…

28Oct 2014 by Vincent Summers No Comments

Analytic Geometry: The Ellipse and the Circle

Mathematics

The circle is really a special type of ellipse. In analytic geometry, an ellipse is a mathematical equation that, when graphed, resembles an egg. An ellipse has two focal points. The distance apart between the two points is one way of describing a particular ellipse. If the two points come together the ellipses become a circle with the point at its center. The equation for an ellipse is, x2/a2 + y2/b2 = 1 In this equation, "a" and "b" are constants that determine the shape of the ellipse, whereas x and y are variables, i.e., they can take on a host of values. When the value for x is known, the value for y is determined. Or, if it is y that is known, then x is determined. If a…

18Mar 2014 by Vincent Summers 2 Comments

Algebra for Beginners: Student Perspective

Mathematics

Have you gone past arithmetic and tried algebra for beginners? Having opted for the “college prep program” at high school, I took Algebra I, freshman year. My instructor was Miss Diamond. She wore those black lace-up shoes elderly women wore then. She was not unkind, although she was rather out of touch with some of the students—including me. It was the first days of class, and, despite seeking her help, I wasn’t getting the concepts. So I turned to the student seated behind me. In about five minutes—perhaps less—he set me straight with his algebra for beginners. I became one of the best students in the class. The principles are easy. Constant -vs- Variable The simplest concept was also the most difficult for me, as paradoxical as that may sound.…

14Mar 2014 by Vincent Summers 4 Comments

Approximate Calculus: Area Under a Curve

Mathematics

Is it possible to calculate the area under a curve with any degree of accuracy? If we have a strong mathematical background, we may say, "Oh, that's easy. It's a matter of calculus." But what if you didn't take calculus? In fact, what if you never even attended high school? Is it possible to achieve an answer? Is it possible to use reason to come up with the principles of calculus? The answer is, indeed it is. I met a man who did just that. He asked me how I would figure the area under a curve. But he did more. He wanted to show how me how he had succeeded in solving the matter himself on his job in construction work. I was so impressed I exclaimed, "You've just…

07Mar 2014 by Vincent Summers 2 Comments

More High School Math

Mathematics

[caption id="attachment_5627" align="alignright" width="400"] Calculations[/caption] The most practical math for people to understand is undoubtedly high school math, rather than college math. After all, how much calculus is used when you go grocery shopping, get your plumbing fixed, or you go skiing on the weekend? High School Math You've got to love it. Here's the first high school math problem. Problem 1: Simplify the mathematical expression: (x-2y3)4 (x-3y4)-2 Simplifying the first parenthetical expression, we get (x-8y12) It is the powers we multiply when powers are raised to powers. Doing similarly with the second parenthetical expression, we get for that (x6y-8) The equation now reads, (x-8y12) (x6y-8) When we multiply numbers, we add and subtract powers. This gives, (x-2y4) [Answer] ------------------------- Problem 2: 2/10 divided by n equals 3-1/2. What does…