1
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When we get to those values of x what's
gonna be true about the sum?

2
00:00:05-->00:00:10
How about Mr. Torelli, what about these
negative function values in this

3
00:00:11-->00:00:16
interval of x Sabrina said the negative
values, what's that gonna

4
00:00:17-->00:00:22
do to the sum? The sum won't be as high.
What do you mean won't be as high?

5
00:00:23-->00:00:26
I think I know what you mean but be
more specific. You know how the line is

6
00:00:27-->00:00:34
going down with the points with the positive.
Ok with the sum it will still

7
00:00:35-->00:00:38
be in the positives, what would keep it
still in the positives? It was more

8
00:00:39-->00:00:44
positive than there is negative. Ok
good and this can be your ruler

9
00:00:45-->00:00:47
measurements. From some of these values
of x there's that much negative.

10
00:00:48-->00:00:56
But there's that much positive so it's
pulling it down but not yet to the

11
00:00:57-->00:01:00
point where the actual function value of
the sum is negative, ok so good.

12
00:01:01-->00:01:04
Alright so we said it starts to decrease,
I think we're still decreasing

13
00:01:05-->00:01:17
when is it going to cross the x axis?
Does it ever cross the x axis? Why not?

14
00:01:18-->00:01:24
What would it take for these two functuons,
for their sum to have a y value of 0.

15
00:01:25-->00:01:31
Or go beyond the x axis. Sabrina? Equal
amounts of positive or negative. Equal

16
00:01:32-->00:01:37
amounts of positive and negative and so did
that ever happen? Does that ever happen?

17
00:01:38-->00:01:42
No so you all agree. Riase our hand if your
graphs do not go back through the x axis

18
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anytime after here, so virually everyone.
So at least you agree on that.

19
00:01:57-->00:02:00
So we're decreasing but we never actually get
into those negatives ok well if we're

20
00:02:01-->00:02:05
decreasing and we never get into those negatives
that means we must start increasing

21
00:02:06-->00:02:10
again somewhere, because if we are on a decrease
right now, Mr Torilli just told us

22
00:02:11-->00:02:18
I should say so we should eventually go
negative unless my functions that do something

23
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that will make me think otherwise