Tuesday, 8 November 2011

chapter 6.5 Making Connections

chapter 6.5 Making Connections

there are 3 application of log function :
1. pH scale http://www.elmhurst.edu/~chm/vchembook/184ph.html
2. Decibel scale http://hyperphysics.phy-astr.gsu.edu/hbase/sound/db.html
3. Richter scale http://www.sosmath.com/algebra/logs/log5/log56/log56.html

those are really good websites that help me to understand it. However, Ms. Joanne Ho did a pretty good work in explaining the applications. :)

chapter 6.4 Power Law of Log

chapter 6.4 Power Law of Log

http://www.es.ucl.ac.uk/undergrad/geomaths/level1/logsnb/MHlogsnbintro8.htm
 this is a very good website for power law of log. really it helps alot to me while studying.
it pretty much covers the whole 6.4


simpler version of it
http://www.purplemath.com/modules/logrules.htm

i would like to end my post with a really great song :

Chapter 6.3 Transformation of Log Functions

Chapter 6.3 Transformation of Log Functions

y = a log (bx + c ) + d

 a = vertically (stretch / compress )
 b = horizontally (stretch / compress )
 c = translate ( left / right )
 d = translate ( up/ down )
*take a pen; write it down; as it will be a helpful tools in the future while dealing with transformation of log functions.

http://archives.math.utk.edu/visual.calculus/0/shifting.6/index.html



chapter 6.2 Logarithms

Logarithms.

First of all, i would like to share a pretty good link for people who wants to learn more about log and exponential function ( from the previous post).
 http://www.themathpage.com/aprecalc/logarithmic-exponential-functions.htm

logarithms ?
The logarithm of a number is the exponent by which another fixed value, the base, has to be raised to produce that number. For example, the logarithm of 1000 to base 10 is 3, because 1000 is 10 to the power 3: 1000 = 103 = 10 × 10 × 10. More generally, if x = by, then y is the logarithm of x to base b, and is written logb(x), so log10(1000) = 3.


The picture shown is a basic formula for a log.


More over, i would like you all to visit the link that ive posted right after this paragraph to increase your understanding on logarithm; as it may be the hardest chapter if you didnt get it really well.
Links :


http://www.sosmath.com/algebra/logs/log4/log44/log44.html
http://www.chem.tamu.edu/class/fyp/mathrev/mr-log.html
http://webmath.amherst.edu/qcenter/logarithms/index.html


thanks :)

Advanced Function Chapter 6.1

Exponential and Its Inverse

exponential functions are useful for describing relationships.
for example, if growth of the population is proportional to the size of the population as it grows, we describe the growth as exponential


however i found a very interesting video of inversing an exponential function on youtube.



ive also found a pretty awesome website :
visit it as it will blow your mind so you dont have to worry about log anymore :)

Monday, 10 October 2011

Chapter 4.5(Prove Trigonometry Identities)


Pythagorean Identity
\cos^2\theta + \sin^2\theta = 1\!

Quotient Identities
\tan\theta = \frac{\sin\theta}{\cos\theta}.

Reciprocal Identities
\sec\theta = \frac{1}{\cos\theta},\quad\csc\theta = \frac{1}{\sin\theta},\quad\cot\theta=\frac{1}{\tan\theta}=\frac{\cos\theta}{\sin\theta}.


The last part of the chapter, proving trigonometry identities. above is some new formulas that quite useful for you to use as you are working on proving.

Chapter 4.4 ( Compound Angle Formulas )

The following are important trigonometric relationships:

sin(A + B) = sinAcosB + cosAsinB
cos(A + B) = cosAcosB - sinAsinB
tan(A + B) =   tanA + tanB
                  1 - tanAtanB

sin(A - B) = sinAcosB - cosAsinB
cos(A - B) = cosAcosB + sinAsinB
tan(A - B) =   tanA - tanB 
                    1 + tanAtanB





Memorize all the formulas above and twist it around (depends on your creativity and the requirement from questions).

Chapter 4.3 (Equivalent Trigonometric Expressions)

we learn this chapter through blended learning, i understand the chapter through my own confusing method, however i could not put it in words to explain. Therefore, i search online and found some really good videos and blog on explaining this chapter in detail.
Here's some of my course mate's blog, i strongly advice you take a look on their blog as you may find some really good explanation on the chapter.

Chapter 4.2 (Trigonometric Ratios & Special Angles)


In this unit, our main focus is on trigonometric ratios and special angles.

There are 6 trigonometric ratios for us to memorize - tangent (tan), sine (sin), cosine (cos), cosecant (csc), secant (sec) & cotangent (cot).

While the special angles are 30˚45˚ and 60˚.

Csc, sec & cot are the reciprocal of sin, cos and tan respectively.



  
this is a picture of a special angle ( sixty degree and thirty degree)


this is another picture of a special angle ( forty degree)

however i found a table in my friend's blog which i think its pretty useful.

It really helps me a lot in understanding the triangle. 
In this chapter, we need to use the CAST rule to calculate the exact value for the triangle. 
What is CAST rule ? 
Well, i found a video about the CAST rule, i hope it helps

Feel free to comment if you do not understand, i will try to explain it in detail :)

Chapter 4.1 (Radian Measure)

In this Unit We are going to deal with π and radian.


Radian measure of angle θ is defined as the length of arc, a, that subtends the angle divided by the radius of the circle, r.


Here's some simple method on how to count radian and degree.