Scribe

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Don't forget that we have our design and measurment test tomarrow morning and our sequence test tomarrow afternoon!

next scribe is ~*~ Just_in ~*~

BOB

Periodic functions was interesting.... Just when you think you have it, it hides in the back of your mind. Maybe that doesn't happen to you, but it does to me. ahahaha. This is going to be a tricky test for me. I get it, I've even participated in class withit, and the homework, but when it comes to talking about it after a nice long sleep, or if we get a break in between, it goes away. I hope i do well on the test though. Just look over the examples, and Jenn's really awesome slide, hehe. and. Bring my lucky rabbits foot, 'but not a real one, that is cruel!'

Good luck on the test!

Scribe

sorry if i don't cover everything in today's scribe. I'm having problems with my computer and had no idea was scribe for today.

OK so today was the first day of our Periodic Functions unit.

To day we looked at the circle, and why there are 360° in a circle. The reason is that 360° is divisible by many numbers, and ever though measuring a circle with 400° may be easier, it cant be divided by as many numbers as 360°.

let me show you (note this symbol † mean divisible by )
360°† 1, 2, 3, 4, 5, 6, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 60, 77, 90, 120, 180, 360

400°† 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400

as you can see, 360 is divisible by a lot more numbers

Next we learned that we measure a certain way, and even though measuring in Jhay-Ar's sounds kinda cool, not everyone knows what it is. So we use radians.


If you take the radius of a circle and measure it around the circumference of half a circle you will notice that it fits exactly the number of π around the half circle. 3.145 .....

This is a radian measurement

it is usually expressed π/ x

half of a circle is 180°.

180° degrees = π



That is why we measure in π. π can also translate into degrees on a circle.
For example

π/2 is half of the circle and since 180° = π then 180/2 is 90° which is half of a circle

π/3 is one third of a circle, 180° = π then 180°/3 is 60°

π/4 is one quarter of the circle there fore 180°/4 is 45°

π/x is a radian measurement


but what about degrees higher than 90°?

lets try
2π/3

well since 180°=π we can substitute π with 180 °

2(280°)/3

2(60°)

120°

the degree is 120°

Here is the diagram. from the slides



OK we in the after noon we were given questions and equations

the equation that we were given was

R/π =D/180°

r represents Radian
π represents π
D represents Degree and
180° represents 180 °

π still = 180°

So the first question we were given was

Find 250° in radians

we solved like this...

r/π = d/180°

r/π=250°/180°

180°r/180° = 250°π/180°

simplify to r=25π/18°

so we just plugged the degree into the right place and crossed multiplied and then simplified



Next Find 3π/8 in degrees

The class solved it this way

d/180°= 3π/8/π
πd/π=180° (3π/8)/π
d=180°(3π/8)/π
d=67.5°

now to me this is a bit much, because of the complex fraction ( a fraction within a fraction ) that and fractions make me angry.

So the way i did it was...

if π is equal to 180° degrees then replace π with 180°

3(180°)/8

3(22.5°)

=67.5°

Both ways are correct, being the lazy person i am, i found a short cut. It just turned out to be a good one, he he.


we also learned what a periodic is. A periodic is something that repeats a rhythm, or a patter. Like the clock, the second hand on a clock will reach its lowest point ( at the 6 ) say now, and reach its highest point (at the 12 ) 30 seconds from now, and then its lowest 30 seconds from then, then reach its lowest point 30 seconds from then and so on and so on. and it never stops. The same thing with the minute hand, excepts its in minutes. and again with the hour hand, except it takes hours. the same thing can be said about a planet, or its moon. It reaches its maximum high at one point and then its minimum point another time and so on. You can find periodical patterns like this everywhere. In a heart beat, seasons, ocean tides, nature and so much more.

We learned this so we could start our homework assignment, the sine curve (graph) thing. Its a hand out so if you didn't get it, ask Mr.K for it.

We leads me to the end of class. Just after the bell we watched a Math parody rap. Called "whatcha no 'bout math". It was kinda funny, i liked it. I wont link it, but of you want to watch it youtube search "whatcha know 'bout math"

hasta luego.

By the way i think I'm the last one on this cycle so there for a new cycle must begin. I suppose ( and if I'm right I'm not sure ... ) the next scribe will be.... mm mm



☺☺☺CRIS_JOHN ☺☺☺

(extra note the ☺ code ALT+1 , if you didn't know)

BOB

PERSONAL FINANCE.... Was fun. It was one of the easiest units for me. I think. It was pretty much straight forward. All you have to do is read and think, read and think... READ AND THINK! ahaha. I really liked it, and i learned how to become a millionare if i live to be 60 ( i say if cause of cancers and other things that, yea ) . I hope i do really well on the test. The only thing im not looking forward to is the questions being long. Super long. GOOD LUCK EVERYONE!

BOB

Ok i know this is MUY MUY MUY TARDES! but my internet was disconnected and ive been busy. BUT its here and i guess its better to have one then not, not umn .. vectors. Well that was short. and easy. I hope i did well on the test. I didnt find this unit as difficult as the last one. I am just hoping that I read all my questions right.
hopefully we can get through personal finance like we did vecotrs.

BOB

OK... so statistics... Well before i start i would like to say sorry if i haven't been up here or anywhere else like the DEV blog thing.. my computer is sick so i had to kidnap my grandma today and force her to bring me home with her so i can use hers... so i can BOB.. YA bob..
So i guess the first thing i would like to say about STATISTICS is that it has frustrated me more than once this term and that I am glad it is almost over.. One thing i noticed was that it was really difficult going through it once with the class and Mr.k. For a while i thought i could possibly fail this unit. The thing that i noticed though was that when i went though it a second time ( on my spare time of course) from the beginning of chapter to the end, it was so much easier because i already had the knowledge that Mr.k had already gave us in my mind. The text book gave me that extra little push into the "I-know-what-I-am-doing-now" zone. I still believe i might have some problems, this isn't an extra easy unit. But the text book helped.. its great to know its not just a paper weight AND it taught me some neat things. Like how i knew that you should clear the Lists and turn off the Y plots when you shade norm. So that's my little blurb about statistics.. GOOD LUCK ON YOUR TEST!!!

Statistics scribe

Ok so today was especially difficult for me, and possibly a few others. We mostly about z-scores and how to find them in many ways.
The first question we were asked to work on was this one.

The following information concerning grades is posted on the bulletin board.

Test Grade    55   65   75   85   95
Z-Score        -2    -1    0    1     2

We were then asked to find the average. There were a number of ways people found it. But I will show you how I found it.

55+65+75+85+95 <- - - - - - - - - - - - I added all the grades together
5 <- - - then divded by the number of grades i added ( which was 5)
=75 < - - - - - - - - - - - -- -- - - - - - and thats how i got 75.

We then were asked which test score had a z-score of -2.76

this means which test score is -2.76 z-score from the standard deviation. The standard deviation is 75.

One way we found it ( which is completely correct )
was

-2.76=x-75 -2.76 is the z-score x is what we want

10 75 is the mean and 10 is the standard deviation
x=75-2.76(10)
=47.4

Now even though that was right. It is long and messy. So mr.k taught us a faster and more efficiant way of solving the problem which is the same thing but skipping 2 of those steps.

X=75-2.76(10)
=75-27.6
=47.4

x is what we want to find
75 is the mean
-2.76 is the zscore
10 is the standard deviation

we want to multiply the z-score we have by the standard deviation which tells us how many grades the grade we are looking for is from the mean. then subtract ( becuase the zscore was a negative number, if it were positive then we'd add) it from the mean, which will give us a score of 47.4

Our next question we were given two people, Tammy and Jamey who both applied for a job. Tammy scores 80 on her provinicial exam and the mean was 70 with a standard deviation of 4.2. Jamey score 510 on her company exam with a mean of 490 and a standard deviation of 10.3. We are to immagine that the company takes these two different exams and make them the same to figure out which one did the best. Who might get the job.

So we firgured out both girls z-scores


tammy jamey
M=70 mean 490
o=4.2 standard deviation 10.3
n=80 her score 510


80-70 510-490
4.2 10.3
=2.83 1.94


We chose Tammy because tammy's z-score was larger. This meant that she was 2.83 standard deviations ABOVE the AVERAGE of the group, where as even though jamey's test score was much HIGHER then tammy's she was only 1.94 ABOVE the average, makeing her average smaller then tammy's
Next we were asked to punch in alot of numbers in to our List1



After we placed all those numbers in our L1
we did this on our calculators

[place picture .c here]

then to draw a histogram on our calculators. If you remember we we to our plots in our calculators andturned it on then chose historgrams. The made sure our xlist was L1 and placed our frequency at 1
To do this we



Then we change our window settings to


Xmin=-6
Xmax=73
Xscl=7.4
Ymin=-10
Ymax=30
Yscl=5
Xres=1

With that we should get a graph like so



Then we were asked if it was normally distubted and we looked at the numbers that we stored.
To figure this out we looked back at the set of numbers we punched into our L1
we also looked at what we stored in S and M, which were the Mean and the standard deviation. If you remembered they were
the M = 49.06
and
the S = 7.3929

The red circled numbers are the numbers within the first deviation of the mean. We found these numbers using what we stored. Remember we stored the MEAN of the numbers we punched in and the STANDARD DEVIATION.

To find -1 of the MEAN we subtracted the S from the M like this

x-o=49.06-7.39
=41.67

then we found the +1 of the MEAN adding S to M.
x+o=49.06+7.34
=56.45

When we counted the red circles up we found 39 numbers within one deviation of the mean. That is 39 numbers our of 50 which means there are 78% of the numbers that are within the first deviation of the Mean. We decided that this was not normally distributed because the normal distribution of data within one deviation of the mean is about 68%.


The red circled.

Ok lets end it with a Mr.K joke ( for those of you who missed it! )



Whats round on the outside and high in the middle?








OHIO... OH! ahahah get it...! OHIO... great joke Mr.K

unfotunately I've run out of time so i cannot finish the second half of the classes scribe till tomarrow afternoon. But if you were wondering who the next scribe is for tomarrow its iss......... TENNYSON
( i am having a bit of problems with the spell check so ... sorry about that )

BOB

Probability, I thought was a scary word. And it was for a while. And even though i still have trouble with it, the diagrams I've been tought to use, like the tree, have really helped alot. I knew before these past few classes that I could use them, but i dont think i was ever really shown how to use them. And that really helped, to be shown to do it and then HAVE to do it in a question. Now the only thing that scares me is that there is alot of work involved. But if things only get harder from here, im kinda not looking forward to movin on. If we could just sit there and work on probability all day I'd be all for it, and thats alot coming from someone with a probability phobia. HEHEHE (>-_-)>

Mutually Exclusive

Mutual Exclisive events





So today in class we got to explore what mutually exclusive events are.


They are events that mutual ( have the same relation with or to each other ) but exlusive, ( or exclude the other ).





EXAMPLE: true and false


You are given a test with true or false questions, you can only choose true or false. You are CANNOT choose both true or false at the same time. If you choose false, then the answer cannot be true, and if you choose true the answer cannot be false. Even though they share a MUTUAL relationship to this situation, the occurrence of one EXCLUDES the occurrence of the other. This is a mutually exclusive event








The Formulla we were given and the situation that we used it in:

Draw either a king or spade in a complete deck of 52 playing cards











A represents the 4 kings that may be drawn and B











During this class we also talked about Independent and Dependent events in relation to Mutually exclusive events








Example


rolling two dice and getting an even sum or double. This is Dependent but Not mutually exclusive.





DEPENDENT EVENTS ARE NEVER MUTUALLY EXCLUSIVE





INDEPENDENT EVENTS can be either MUTUALLY EXCLUSIVE or NOT





There were more questions we worked on and even though i didnt quit get it at first working through it in class helped. I'm still a bit fuzzy on it. But feel free to refer to the slides if you wish.. I hope this isnt too flashy. When i see that I can use HTML and i REALLY use HTML and... hehehe ... and the next scribe is..drum roll please.... (>n_n)>~-( DRUM ROLLLING )-~<(n_n<) .... Jhay-Ar

BOB

Well when I was first introduced to matrices, it looked a little difficult until Mr.K showed us that we can use our hands to do this, it sparked some interest in me. I'm a kinesthetic learner, which basically means I'm a physical learning or I learn with my hands. So grasping how to add and subtract and multiply wasn't difficult at all because I could use my hand and memorizing the rules wasn't to bad either. That was UNTIL the latest homework assignment on the hand out "Transition Matrices." For some reason i can't get past creating the matrices, because of a one little word. PROBABILITY. It is almost like I have a phobia of probability, because any time i see it my mind goes blank. Which is understandable because that isn't one of my strengths in math. But that is OK because that tells me what I need to work on. Anyways, I may not be able to get them on my own, But it helps a lot to go over what i don't get in class. It wasn't until being in class and talking to people did i understand what I did wrong. Mr.K was so right, Learning is a conversation!