Mathemathical Formulas

DKnightJ · #1 07-19-2008, 05:20 AM

This is too help others as well, but this is a thread for people to contribute and ask for Maths formulas...

Currently Needed are:

-Trignometry
-Shapes, Prisms, Surfaces, Volumes (how to do)
-Consumer Arithmethic Formula

Thanks =)

cybercrash · #2 10-01-2008, 08:49 AM

for volume it is just surface area x height, some ppl waste time rmb lxbxh rx2 etc...
but it's just surface x height , for example a cube of 5x5x5, the surface below is 5x5 = 25 then times the height, 25x5 = 125 = volume.

Formula (for the arithmetic series)

Express the arithmetic series in two different ways:

S_n=a_1+(a_1+d)+(a_1+2d)+\dots\dots+(a_1+(n-2)d)+(a_1+(n-1)d)

S_n=(a_n-(n-1)d)+(a_n-(n-2)d)+\dots\dots+(a_n-2d)+(a_n-d)+a_n.

Add both sides of the two equations. All terms involving d cancel, and so we're left with:

\ 2S_n=n(a_1+a_n).

Rearranging and remembering that an = a1 + (n − 1)d, we get:

S_n=\frac{n( a_1 + a_n)}{2}=\frac{n[ 2a_1 + (n-1)d]}{2}.

**Sean** · #3 10-01-2008, 09:26 AM

You guys should just type the formulas up in word (using equation editor) and than convert the document to PDF format and upload it.

JosexD · #4 10-01-2008, 06:50 PM

I'm argentinian so I naturally speak spanish, so I've just only copied these from wikipedia ^^

The sine function (sin), defined as the ratio of the side opposite the angle to the hypotenuse.

The cosine function (cos), defined as the ratio of the adjacent leg to the hypotenuse.

The tangent function (tan), defined as the ratio of the opposite leg to the adjacent leg.

Good Luck!!

Frank · #5 10-07-2008, 11:37 PM

An easier way to remember that trigonometry euqtion mentioned above is

Quote:

SohCahToa

which stands for:

Quote:

sin Opposite/Hypotenuse, cos Adjacent/Hypotenuse, tan ToOpposite/Adjacent

.

Shapes:

To find the perimeter of something, add up all the sides (if there is one side missing use Pythagoras's theorem to find it, the formula for Pythagoras is usually c2 = a2 + b2 (c squared equals a squared plus b squared).

To find the AREA, there are different formulas for different shapes:

Code:

triangle = half of base multiplied by height

Code:

rectangle = width x length

Code:

square = side x side

Code:

circle = pi x diameter (or 2pi x radius).

Code:

Volume of a rectangular prism = length x breadth x height

Code:

Volume of a cube = length x breadth x height
Hope this helped.

prettykitty1337 · #6 10-31-2008, 04:17 PM

this site guides u to trigonometry.

**Sean** · #7 11-01-2008, 10:30 AM

lol @ Frank, didn't know they taught SohCahToa in Australia. Small world.

+alfy619 · #8 11-01-2008, 09:12 PM

Trig Distant formula from memory i think its root (y2-y1) + (x2-x1)