hw#3-8 Due Thurs Dec 1st
pg 218-219 #10-21 ALL
#23-29 Odd
pg 220 #49-63 ALL
You should be looking at pg 223-226 #1-61 ALL in preparation for the UNIT 3 TEST, which is scheduled for next Wednesday.
You do not have to DO #1-61 All, but you should be doing some of them and looking at all of them.
You do not have to DO #1-61 All, but you should be doing some of them and looking at all of them.
Can you explain number 38 and 39 on page 225...I dont really inderstand how to list the subsets in the sets: {s,t}
ReplyDeleteand also, : {5,10,15}
I looked at the example but I still cant quite understand what to do...
thanks
A subset is a partial set of a complete set.
ReplyDeleteSubsets of a place SETting of a knife, fork, and spoon could be:
1) a knife
2) a fork
3) a spoon
4) a knife and fork
5) a knife and spoon
6) a fork and spoon
(note: order does not matter in a set, so a spoon and fork is no different than a fork and spoon)
7) a knife, fork, and spoon
8) nothing - aka the null set which can also be written as {ø} or {}
Notice that a subset can be equivalent to the full set, but not in excess.
A knife, fork, spoon, and soup spoon would not be a subset... it's actually known as a superset!
lmk if this helped...
thanks I think I got it now
ReplyDeleteGET SOME SLEEP!!!
ReplyDeleteI dont get how to answer the A U B ones... like ALL the problems on page 218 confuse me. Can you explain how to answer them?
ReplyDeletewait i think i got it but still explain it for fun. Just for giggles.
ReplyDeleteLet's say Set A={1,2,3,4,5}
ReplyDeleteSet B={3,4,5,6,7}
A ∩ B ={3,4,5}
... because those are the shared elements, i.e. the elements that both set have in common.
A U B = {1,2,3,4,5,6,7}
... because that is the gathering of all of the elements of both sets, without any duplication.
We will be going over several other examples in class tomorrow.
But what if B is x? then how would you list it. For ex. problem 10 is A U B. A={1,3,4} B={x|x is an even whole number less than 9}how would u do this problem?
ReplyDeleteSo I'm confused on #44 on page 220. I don't undestand how to solve it. I hav the venn diagram set up , but i don't know what to do next. help anyone?
ReplyDeleteIm confused on number 50 on page 220. Can someone please help!?
ReplyDeletenvm i got it for number 50
ReplyDeleteA={1,3,4} B{x/ x is an even whole # less than 9}
ReplyDeleteA U B= {1,2,3,4,6,8}. union set or U is when you have to list all of the #'s in both sets. if number shows twice, once in each set, only right it once in the union set
i meant to say write not right
ReplyDeleteFor #10, B could be listed in ROSTER FORM as well (remember, the notation is a choice thing)
ReplyDeleteA={1,3,4}
B={0,2,4,6,8}
A U B = {0,1,2,3,4,6,8}
fyi A ∩ B = {4}
do you ∩ answer?
I missed last class and the link helped but how do you write out your answer for example i figured out the answer for #29 but don't know how to write it
ReplyDeletepg 220 #44 is a bit tough to explain... you need to draw a universal set "rectangle" with a circle each for A & B intersecting within. Let's save that one for our review day tomorrow in class.
ReplyDeleteFor @29, I have a long answer and a short answer.
ReplyDeleteThe verb form of union is unite. Unite means to put together to form a single unit. Union is symbolized by the letter U, which is the first letter of unite. In set notation, UNION is synonymous with the word OR.
The verb form of intersection is intersect. Intersect means to share a common area. (Note: in real life, when you talk about the "intersection" of two streets, you are talking specifically about the "square" between the walkways where that both streets share). Intersection is symbolized by an upside-down "n" which is the first sound of the word intersect. In set notation, INTERSECTION is synonymous with the word AND.
The SHORT answer?
{x| x>-3} AND {x|x≤19/3}
{x|x>-3} ∩ {x|x≤19/3}
{x| -3<x≤19/3}
are all equivalent answers
So on the review i am confused on question 31: 3t>5t+12
ReplyDeleteSo what don't we like? The variable on both sides, right?
ReplyDeleteTry removing 3t from both sides... what's the result? (Hint: Zero is a number!)
so for the 3t>5t+12 do you divide? I think that's what you do but I'm not completly sure
ReplyDeleteCan you explain compliments of a variable please it's one thing that really messes me up and I don't want it to result in my tests and thanks for posting the videos on solving inequalities my algebra confusion cloud is getting a little bit clearer :)
ReplyDeleteA comPLIment of a variable would be something like... "Hi there x, that's a lovely coefficient you have on today."
ReplyDeleteWhat you are asking about is the comPLEment of a SET. A complement of a set can only exist if both a UNIVERSAL SET and a subset have been designated.
So, if the set of natural numbers (i.e. 1,2,3,...) is the Universal Set and the Set E represents the set of even natural numbers, then E' is the set of odd natural numbers. Set E' is the set of elements that, when combined with set E, makes up a complete Universal Set.
Often, Set U is id'd as the Universal Set.
If Set U={1,2,3,4,5}
and Set A={1,4} then what is A'?
All that is being asked is what elements need to be combined with the elements in set A in order to make a complete Universal Set.
Clearly (I hope) in this case, A'={2,3,5}
Ca-peesh?
btw, I will be available before school (7:15) AND after school (2:30-4:00) on Tuesday.
ReplyDeletei'm planning a video lesson for Chapter 3 Review #31... 3t>5t+12... should be ready by 8pm.
ReplyDeleteAs promised, here is the Video Lesson for 3t>5t+14.
ReplyDeleteHope it helps!!
(oops, it was supposed to be 5t+12, but you'll still get the jist!)
Someone asked about #57 in the Chap3 Review... the nail problem where acceptable lengths of a nail had to be no more that 0.4mm away from the standard length of 20mm.
ReplyDeleteWell, 0.4 less is 19.6mm and 0.4 more is 20.4mm, so if x is the length of a nail
x≥19.6 AND x≤20.4
which could also be written as:
19.6≤ x ≤20.4
for set-builder fans:
{x|19.6≤ x ≤20.4}
of course, interval notation fans would like to see:
[19.6,20.4]
It's a smorgasbord of set notation!! Woo-hoo!!!