### Scribe #11

Sorry about the big delay on this, but I really tried my best to do this on time. I also apologize for falling asleep in class. That was pretty bad, but it was kind of funny that Marcquin had to poke me in the arm pit. Alright, so I, Jessica, was the scribe for

**YESTERDAY'S**class. Yeah, I know I took long but I finished it!

Okay, so we had two classes, and in the morning Mr. K briefly addressed the class to get our blogging on blogging done. Why? Simply because the sooner we do it, he can help us with what we're struggling with, and we won't have such a hard time on the test on Friday. As we can see, what he said really did work. So Mr. K changed up what he had orginally planned out to do today [erm, I mean yesterday], and we worked on drawing sinusoidal graphs and determining the equation of a given graph.

We were given 2 equations to draw, which were:

y=sin2(x - π/2) +1

**and**

y=2cos3(x + π/6) -1

They ended up looking like this:

We were also given 2 graphs to find the sinusoidal equations of.

1.

This graph was determined as : y=3/2sinx

Technically speaking, there is more than one answer for any graph, and that there is an infinite amount of answers. This graph could've also been determined as:

y = -3/2cos3(x + π/6)

y = 3/2cos3(x- π/6)

y = -3/2sin3(x - π/3)

2.

This can be determined as y = 2sin π/2 +1

**OR**y = 2cos π/2(x-1)+1.

Then, in the afternoon, we were given a group problem to solve within fifteen minutes. Basically, you're on a ferris wheel that's 100 ft long, but you also must consider that the seat is 3 ft off the floor, so your maximum height would be 103 ft. It takes 15 seconds for one revolution and we were suppose to write this out as a funtion of time.

The answer we ended up with was **f(t) = -50cos 2π/15 +53 OR f(t) = 50sin 2π/15(t-3.75) +5****0.**

After that we copied some new things into our math dictionaries.

**THE RELATIOINSHIP BETWEEN SINE AND COSINE**

sinx = cos(x - π/2)

cosx = sin(x + π/2)

They are related by a phase shift of π/2.

__UNIT 2 - TRANSFORMATIONS__**Translations**f(x - a) + b

The Role of Perameter a

*** [ NOTE: Where I've written in "is less than" just put < OR < in place of that. I wasn't able to use the "<" signs because it messed up the html coding and it looked all wrong. ]

a>0 The graph of

**f**shifts RIGHT in a units

∙a increases the x-coordinates of

**f**by a units

a [is less than] 0 The graph of

**f**shifts LEFT in a units

**∙**a decreases the x-coordinates of

**f**by a units

The Role of Perameter b

b>0 The graph of

**f**shifts UP b units

b [is less than] 0 The graph of

**f**shits DOWN b units

∙The y-coordinates of

**f**are changed by b units

And that's pretty much everything we covered yesterday. I know it's not immensly detailed, but I tried and hopefully it's helpful enough. For today's class, I chose

**Marcquin**to be the scribe, so good luck with that.

## 1 Comments:

Nice graphs, Jessica =)

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