Homework for 4/29

Some of us didn't understand problems 41 and 43 from the previous hw. Could you please post them here? Thanks.
Petra

Homework question

So I understand problem 55 up until you come out with sin x = {3/4, 1/3}. However, I simply did arcsin(3/4) and arcsin(1/3) and came out with x?{.8481,.3398}. However, the book showed two other answers that I should get, and I understand that they are also points on the arcsin graphs. However, I don't understand why we use two of them on each graph. Shouldn't the arcsin function only have one value for x? And even if it did use more than the one, then how would I know which to use when there are infinite points on the arcsin graph? Furthermore, how would I calculate the other value? It gives ~2.2935 as one of the values, and if I enter in sin(2.2935), i get ~.75. But I don't know how to find that without having it in the book. Thanks!

-Molly

A great read

Heading off to an elite school after CHRHS? You should definitely read this article:

http://www.theamericanscholar.org/the-disadvantages-of-an-elite-education/


Enjoy!

Mr. O'B

Homework for 10/27/09

I was unclear on how to do pg. 159(37). Could we go over this in class? Thanks!

- Molly W.
W-2 Pre-AP Calc

HWK assigned10/18

I had trouble on problems p.134/23 ,79, p.149/21, 29, 33, 41. I forgot how to put parabolas in standard form and also forgot what a and b are in the equation for the axis of symmetry.
-Henry W-2

Homework for 9/21/09

Hey Mr. O'Brien. Can we go over 79/25d, 31d, and 61 in class? Thanks!

- Molly

How to find a line of best fit on TI-84 Plus

Someone asked how to find a line of best fit on the graphing calculator, so I'm putting it on here... This is how I do it on my TI-84 Plus, but it's probably similar for everything else.

Linear Equation
To find the line of best fit for a linear equation, pretend we had the points: (-2, 5) (1, 11) (3,15)
Go to STAT > Edit... Under L1, enter all the x-coordinates. Under L2, enter all the y-coordinates. Then hit STAT > CALC > LinReg. Hit ENTER. You'll see something like this:

LinReg
y=ax+b
a=2
b=9
This means y=2x+9.

Quadratic Equation
Say you have a quadratic with these points: (-2, 3) (0,-5) (2, 11) (3, 28)
Go to STAT > Edit... Under L1, enter all the x-coordinates. Under L2, enter all the y-coordinates. Then hit STAT > CALC > QuadReg. Hit 2nd>1 (L1), then enter a comma, and then 2nd>2 (L2). Then hit ENTER. It will give you something like this:

QuadReg
y=ax²+bx+c
a=3
b=2
c=-5

This means that the equation is y=3x²+2x-5

Cubic Equation
For a cubic equation, enter the points. Pretend they're (-2, -8) (-1, -6) (0, -6) (1,4) (2, 36)
Go to STAT > Edit... Then enter all the x-coordinates under L1 and the y-coordinates under L2. Then hit STAT > CALC > CubicReg. Type 2nd>1 (L1), comma, then 2nd>2 (L2). Hit ENTER. You'll see something like this:

CubicReg
y=ax³+bx²+cx+d
a=2
b=5
c=3
d=-6

This means it's y=2x³+5x²+3x-6.

Good luck :)

Homework for 9/15

Could we go over problems p.49/89 and p.63/47. I got an answer, but I would like to review them. Also I could use a quick review on graphing calcs. Tyler from my W-2 class gave me a good overview on how to use them on the homework problems, but I don't know how to use them for other types of problems.
Thank you,
Henry W-2

Superfluous technology use

We have spent far too much class time subscribing to your blog.