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Math History
Far more interesting than one might first expect, the history of mathematics is filled with bitter rivalries, political machinations, and incredible innovations by some of the most amazing minds in history. Post all questions concerning individual mathematicians, the development of mathematical theories, and the sociological impact that resulted into this category.
3,988 Questions
Whats the area formula for a hexagon?
P=perimeter s=sides h=altitude (distance from the center to a side at a right angle)
A=1/2aP
or
A=1/2(6s x a)
Edit - If the hexagon is regular, the area can be found by this formula:
3s^2 * 3^(1/2) / 2
Where s=side length of the hexagon and in this case squared and 3^(1/2)=square root of 3
In a lot of different places!
Obviously in geometry. It occurs in the formulas for the circumference and area of a circle, and for the surface area and volume of spheres, cylinders and cones. In mechanics, the formulas for moments of intertia of spheres, cylinders, and so on, involve pi.
Pi also occurs in trigonometry, and is involved in the definition of radian measure (2 pi radians = 360 degrees). Radian measure is used when trigonometric functions are combined with calculus, and that combination has connections with many parts of physics and engineering.
For instance, Fourier series arise from the combination of trigonometry and calculus. Fourier used them to solve problems connected with the distribution of heat in physics. Now they are used in all sorts of places, including acoustics, image analysis, and engineering problems like analysing the behaviour of the digital-to-analogue converters used in CD players and portable audio devices. The formulas for Fourier series involve pi.
There is also a connection between trigonometry and complex numbers, shown in Euler's identity e^(i pi) = -1 (where ^ means "to the power of"). Again, complex numbers are used widely in physics and engineering.
Another place that pi occurs is in probability and statistics: the formula for the normal distribution, which is used all the time in probability and statistics, involves pi.
There is more ...
In summary, if you look at almost any technical field that has some mathematics at its base, you will find pi.
There are 6 circles1 of the circles is shadedWhat fraction of the circles are shaded?
1/6 because OOOOOO
How is a square alike and different from a rectangle?
A square has four sides of equal length. A rectangle has lengths that are different from the widths.
What is the magnitude of the size change of the figures formed by these matrices?
There are no matrices in the question!
What does micro-inch finish mean and how is it measured?
micro means 10 to the -6 inches so for example 32 microinches would be 0.000032 inch. With respect to surface finish it is basically a measure of the height of the "peaks and valleys" of the finish of a surface. There are different ways to measure this (RMS, etc.) but that is basically what it means. So for example a 125 microinch finish is a typical machined fnish for metals but a 32 is much better and would be called out where sealing surfaces may be needed.
What number do you call in a emergecy?
It depends what country you're in ! In the UK, it's 999 - in Europe, it's 112 - in america it's 911.
