trustle's home > Sea of English > Mathematics | 17 | T
in trustle's webmarks all the webmarks

BC 0800? Roman Numerals | R
The Romans showed numbers into the thousands using these 7 symbols: I for 1, V for 5, X for 10, L for 50, C for 100, D for 500 and M for 1000.
http://qindex.info/d.php?c=4758#5038
/* Regular Expression
M{1,3}
((C{1,3})([^DM]|$))|(CD)|(DC{0,3})|(CM)
((X{1,3})([^LC]|$))|(XL)|(LX{0,3})|(XC)
((I{1,3})([^VX]|$))|(IV)|(VI{0,3})|(IX)
*/

// Javascript
function 2arabic(c) {
    switch(c) {
        case 'I': return    1; break;
        case 'V': return    5; break;
        case 'X': return   10; break;
        case 'L': return   50; break;
        case 'C': return  100; break;
        case 'D': return  500; break;
        case 'M': return 1000; break;
    }
}

var roman = 'MCMLXVIII';
var arabic = 0;
var previous = 0;
var current = 0;
for(i=0; i<roman.length; i++) {
    current 
        = 2arabic(roman.charAt(i));
    if(previous && previous<current) 
        arabic -= previous;
    else arabic += previous;
    previous = current;
}
arabic += current;

BC 0570 - 0495 Pythagoras | R
How many ways are there to prove the Pythagorean theorem? - Betty Fei
http://qindex.info/d.php?c=4758#5039

BC 0500? Pythagorean Mathematicians | R
Their dictum of "All is number" suggested that numbers were the building blocks of the Universe and part of this belief was that everything from cosmology and metaphysics to music and morals followed eternal rules describable as ratios of numbers.
http://qindex.info/d.php?c=4758#5017

BC 0500? Hippasus | R
According to Pythagoras theorem the diagonal length of a square with each side measuring one unit would be square root of two. The assumption that square root of two could be expressed as a ratio of two integers deduces a contradiction.
http://qindex.info/d.php?c=4758#5026

BC 0384 - 0322 Aristotle | R
The ancient Greek philosopher Aristotle taught that heavier objects fall faster than lighter ones.
http://qindex.info/d.php?c=4758#4905

08th century Hindu-Arabic numeral system | R
By the 8th century, Indian mathematicians had perfected positional notation and over the next several centuries, Arab merchants, scholars and conquerors began to spread it into Europe.
http://qindex.info/d.php?c=4758#4984

1202 Leonardo Fibonacci | R
Fibonacci asked himself how many pairs of rabbits originated from a single pair in one year. Each pair of rabbits will produce exactly one more pair of both sexes per month which in turn would be fertile from the second month after birth.
http://qindex.info/d.php?c=4758#4759

1564 - 1642 Galileo Galilei | R
Galileo's inspired use of a ramp had shown falling objects follow the mathematical laws. The distance the ball traveled is directly proportional to the square of the time.
http://qindex.info/d.php?c=4758#5036

1643 - 1727 Isaac Newton | R
Galileo had already discovered some years prior that the distance traveled by a falling object is represented by a function of time. Newton wondered how one could calculate the velocity of the object at any particular instance during the fall.
http://qindex.info/d.php?c=4758#5035

1646 - 1716 Gottfried Wilhelm Leibniz | R
Leibniz did similar work just a few years later, independently of Newton, and it is actually his notation that we still use today.
http://qindex.info/d.php?c=4758#5027

Crisis in the Foundation of Mathematics | R
Infinite Series
http://qindex.info/d.php?c=4758#4835

Defending Zeno's Paradox | R
Defending Zeno's Paradox
http://qindex.info/d.php?c=4758#5023

Euclidian Geometry | R
A point is nothing more than a location in space. It is zero-dimensional. From here we can create a one-dimensional object called a line by stringing an infinite number of points along a particular dimension.
http://qindex.info/d.php?c=4758#5030

Euclidian Geometry | R
By stringing an infinite number of lines along a dimension perpendicular to the line, a two-dimensional object called a plane can be obtained. And then if we string an infinite number of planes in either direction, we get three dimensional space.
http://qindex.info/d.php?c=4758#5031

The Map of Mathematics | R
The Map of Mathematics
http://qindex.info/d.php?c=4758#4834

Tom Campbell | R
Zeno's Paradoxes Solved by MBT Science Model
http://qindex.info/d.php?c=4758#5024

Zeno's Paradoxes | R
Zeno's Paradoxes
http://qindex.info/d.php?c=4758#5025
execute:0.082 sec, load: sec http://qindex.info/d.php?c=4758 [ refresh ] [ Email to trustle ]
Qindex.info 2004,   Introduction | 소개 | 介绍 | 導入 | qindex.info@gmail.com