Monday, March 29, 2010

Algebra4


Dear alien,

Today I want to tell you about multiplication. A multiply is a method for finding the probability that both of two events occur. We use in it some numbers or variables that we called it by names maybe you don’t know it. First, a multiplicand is the number that gets multiplied. For example, in 6 x 3 = 18, 3 is the multiplicand. Second, a multiplier is the number that you are multiplying by. For example, in 6 x 3 = 18, 6 is the multiplier. Finally, a product is the answer when two or more numbers are multiplied together or we can say it is the result of multiplying a set of numbers or expressions. That is what I have today to tell you about. I’ll tell you more in next time. Have a good day.














Important Formula:
Sin(q) = Opposite / Hypotenuse
Cos(q) = Adjacent / Hypotenuse
Tan(q) = Opposite / Adjacent
Cotan(q)= Adjacent / Opposite
Secant(q) = 1 / cosine
Cosecant(q) = 1 / Sine



Example :








Let's saythat a = 3 , b = 4 , c = 5
Sine(q) = a / c = 3/5
Cosine(q) = b/c = 4/5
Tan(q) = a/b = 3/4
Cotan(q) = b/a = 4/3
Secant(q) = 1 / cosine(q) = 5/3
Cosecant(q)= 1 / sine(q) = 5/4
it's really interesting to study math!

arc length formula

The arc length for a sector of a circle is given by the arc length formula S = r.θ

Here S - represents the arc length - represents the radius of the circle

θ - represents the angle in radians made by the arc at the centre of the circle

The application of the arc length formula can be better understood with an example

Find the length of the arc using the Arc length formula which subtends an angle of 60 degrees at the centre of a circle whose radius is 5 cms.

Step1: The angle subtended by the arc is given in degrees. So need to convert the angle in to radians using a simple formula.

π radians = 180 degrees
Divide both sides by 3
π/3 radians = 180/3 = 60 degrees

Arc Length Formula

Now we have the radian measure of the angle as pi/3, the radius is given as 5 cms, apply the arc length formula S = r.π

S = 5 . π/3

We know the value of &pi is 3.14 (approx) but to get a more precise value key in the computation using your graphic calculator.

So arc length S is given by 5 . π/3 = 5.2359 cms

Note: The radian measure of an angle is used instead of the degree measure to simplify the arc length formula.

Thursday, March 18, 2010

Maximum and minimum of function

One day, my small brother came to me, and he asked me what is the maximum and the minimum of a function? Then I said "Hmm, do you know how to drow a function?" Then he said "Of course" Then I said "If you have a function and you draw it, you'll find a maximum point and a minimum point. Likne this picture.
Then he understood it.
He said that the mathematics is a beautiful world. Then I said " I totaly agree with you".

Tuesday, March 2, 2010

Algebra3

Dear alien,

Remember last time we studied addition. The addition has some property when you do the sum of thing. Zero property is one from the addition properties, and we can say it’s the sum of zero and a number when you add them together it will be the same as that number, for example (5 + 0 = 5). When we use the variable in any equation and we want to know how much the variable? We use the equation to know the solution of that variable, for instance (A + 0 = 5) the solution of A will equal 5. That’s what I have now next time we will have a new thing for you.

Tuesday, February 23, 2010

My story with my new friend

One day , I met starnge man . He said that he came from the moon. Then I said to him , what it's your name?. He said " I don't have a name" . Then I gave him a name . It was John. Next month, he said I want know what does Algebra mean ? . Then I it's related to math . I said to him " do want to count anything ? " . Then he laughed , and he said " I want know my vehicle's speed" . Then I said " How many hours it takes from the moon to here" . He said it's X hours. Then I said to him " The distance between the moon and the earth is Y . So if you want to know your vehicle's speed. You must divide the distance by the time, and you can write it like this ( Y/X = your vehicle's speed) " . Then he said "Oh I see" . So he learned a part from math and physics. Then he said " Thanks!" .
THE END

Wednesday, February 17, 2010

Algebra2

Dear alien,

I think there are much information for Algebra you need it, and as I said Algebra is important for our life. I was thinking a lot about what should I tell you about this time, and what are the most important things you should to know before we going on it or going to higher level, and please tell me if you can’t understand any things or if you have any problems with it. Today I’ll talk about the addition. You can with addition add something to others, and others or the numbers we called it by addend. For example let’s say (a + b = c) The variables (a) and the (b) are the addends, and we add (a) to (b) by the symbol plus (+), and that mean to add, and it’s equal (c). The equal here is meaning the sum of this equation.