Scribe Post 4/13/11-Adan D.

Today we learned how to prove and not prove identities. We learned the steps and we did examples. Steps(proving not an identity): 1) Plug a value into each side of the equation 2) Simplify both sides 3) check and see if they equal each other. Steps (proving an identity): 1) start with the more complicated side of the equation 2) use cos/sin to simplify 3) other strategies like factoring, and foiling may help. We also learned that you need to know the identities in order to be able to prove identities. Two examples we did are 2sin=sin(2) and 1+secx sinx tanx= sec^2x.

Next Scribe: Alex

John Henry Scribe Post April 12, 2011

Today in class we went over homework involving Identities. Incase you haven't learned them here is a link to Kelsey's Scribe Post about them.

These are Odd/Even Identities:

sin (–x) = –sin x cos (–x) = cos x tan (–x) = –tan x

csc (–x) = –csc x sec (–x) = sec x cot (–x) = –cot x

These are the Basic Identities:

These are the Pythagorean Identities:

sin² θ + cos² θ = 1

tan² θ + 1 = sec² θ

cot² θ + 1 = csc² θ

Next Scribe: Irfan

Elijah Scribe Post - 3/31/11

Today in class, we talked about An identity is an equation that is satisfied by every number for which both sides are defined. Identities can help combine terms when dividing and multiplying. There are infinitely trigonometric identities, but only the most common identities should be memorized.

Reciprocal Identities

sin(x)=1csc(x) cos(x)=1sec(x) tan(x)=1cot(x)
csc(x)=1sin(x) sec(x)=1cos(x) cot(x)=1tan(x)

Tangent and Cotangent in Terms of Sin and Cosine

tan(x)=sin(x)cos(x)
cot(x)=cos(x)sin(x)

Pythagorean Identities

sin2(x)+cos2(z)=1
1+cot2(x)=csc2(x)
tan2(x)+1=sec2(x)

Odd/Even Identities

An odd function is one for which f(-x)=-f(x) and an even function is one for which f(-x)=f(x)
Odd Identities:

sin(-x)=-sin(x)
csc(-x)=-csc(x)
tan(-x)=-tan(x)
cot(-x)=-cot(x)

Even Identities:

cos(-x)=cos(x)
sec(-x)=sec(x)

Scribe Post -Adan D: March 29, 2011

Today we learned more about graphing sine, and cosine, functions. On the unit circle:

sin α= y cosα=x tanα=y/x cscα= 1/y secα=1/x cotα=x/y

We also learned how amplitude changes the y values of the graph and how it is always positive. We also learned about the graph's period, which is the interval it takes for a sin or cos function to complete one cycle. Here is an example of a sine function:

Scribe Post March 1st Irfan

Today, we went over problems 1-16 that we had been assigned to finish. Many people in the class were thinking that trig has to do with side lengths, but we learned that it was not side lengths, but ratios. At the end of this post will be a website that you can go on to learn more about trigonometric functions. We also had time to catch up with other work in class.

Can you do Division? Divide a loaf by a knife - what's the answer to that? ~Lewis Carroll, Through the Looking Glass

Here is the link to the website that you can go to for extra help.. You can also google trigonometric functions

http://www.math-mate.com/chapter26_2.shtml

Elijah's Scribe Post - 2/28/11

Today in class we learned about trigonometric functions. Jojo drew a picture of a right triangle on the board and labeled an angle adjacent to the hypotenuse theta. In this triangle, the hypotenuse is labeled r, the vertical leg is y and the horizontal leg is x. Sine, cosine, and tangent are side ratios that you can use to determine unknown angles and sides of triangles. Sine (sin) is the ratio of opposite side over the hypotenuse, or y over r. Cosine (cos) is the ratio of the adjacent side over the hypotenuse, or x over r. And Tangent (tan) is the ratio of the opposite side over the adjacent side, or y over x. This can be remembered by the word SOHCAHTOA which stands for:

Sine
Opposite
Hypotenuse
Cosine
Adjacent
Hypotenuse
Tangent
Opposite
Adjacent


Or as it relates to our math class:

Signs
Of
Hovercrafts
Can
Actually
Harm
Teachers
Of
Arithmetic


Trigonometry is a sine of the times. ~Author Unknown

Adan Scribe Post: Day 13- Feb. 22 2011

Today Jojo sarted teaching section 1.2 which is about radian measure. A radian is the measure of and arc's length. He talked about how in the radian system of angular measurement, the measure of one revolution is 2pi, half a circle is pi, each right angle is pi/2 and so on. He also talked about the most common measurements and their degree. Here are some of those:

pi/4 = 45 degrees

pi/3 = 60 degrees

pi/6 = 30 degrees

2pi/3 = 120 degrees

and so on.

John Henry Scribe Post 2/9/2011

Today Jojo explained the quadratic formula F(x)= ±a(x±h)±k

F(x)= ±a(x±h)±k

determines where on the x axis the shape is

determines where on the y axis the shape is

Whether or not on x axis

a >1 stretch

01

here is a website with some great examples:

http://uncw.edu/courses/mat111hb/functions/inverse/inverse.html

you can also use page 33 in your book

next scribe: Kelsey

Elijah Scribe Post - 2/8/11

Today we discussed functions. We had a long debate about whether the area of a circle is a function. We came to the conclusion that a circle is not a function because it has more than one value for x for each value of y. Since it is the day after the Super Bowl, I decided to find out if the area of the outline of a football is a function. It also is not a function because of the same reason as a circle.