Length: 16.5 minute(s)
Subject: Math - Algebra II
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[00:00:00] *** Please note: All sessions are recorded for quality control. ***
[00:00:00] Tool Added > Whiteboard
Nathan (Customer)
[00:00:00] the number of paramecia grew exponentially. At first there were 400,000. 3 days later there were 1,200,000. How many would there be after 8 days?
Madhu T (Tutor)
[00:00:04] Thanks for signing on! How are you?
Nathan (Customer)
[00:00:07] Hi again!
[00:00:12] good, how are you?
Madhu T (Tutor)
[00:00:28] I am well, thank you for asking!
[00:00:43] Have you worked with exponential problems before?
Nathan (Customer)
[00:00:47] aa little
Madhu T (Tutor)
[00:00:58] That's great! Did you try anything on this one?
Nathan (Customer)
[00:01:04] no, not yet
Madhu T (Tutor)
[00:01:30] Take a moment to read it and let me know your ideas on how to begin
Nathan (Customer)
[00:01:55] first we need to find the growth factor?
Madhu T (Tutor)
[00:02:07] Very good!
[00:02:12] Click on the pencil to write on the board
Nathan (Customer)
[00:02:29] I don't know how we would do that though
Madhu T (Tutor)
[00:02:50] Let's see, is there an exponential function that you have used in class?
[00:02:59] There is a basic format, and your teacher may have shared that with you
Nathan (Customer)
[00:03:08] one sec
[00:03:27] yes
Madhu T (Tutor)
[00:04:02] Nice!
[00:04:09] Do you know what each of these stands for?
Nathan (Customer)
[00:04:14] yes
Madhu T (Tutor)
[00:04:15] At, A0, k, and t
[00:04:27] You mentioned finding the growth factor first.
[00:04:30] So we do exactly that
Nathan (Customer)
[00:04:38] which would be k, correct?
Madhu T (Tutor)
[00:04:42] Correct!
[00:04:46] What is A0 ?
Nathan (Customer)
[00:04:45] or e^k
[00:04:58] 400,000
Madhu T (Tutor)
[00:05:04] Good!
[00:05:21] What is t =
Nathan (Customer)
[00:05:26] 3
Madhu T (Tutor)
[00:05:40] Good! And A(t)
will be
Nathan (Customer)
[00:05:49] 1,200,000
Madhu T (Tutor)
[00:06:04] Any questions on what we have so far?
Nathan (Customer)
[00:06:07] no
[00:06:11] not yet
Madhu T (Tutor)
[00:06:17] This will help us get the value of k
[00:06:28] Then we go back and plug it into our formula. Eventually, use it for t = 8
[00:06:32] Makes sense?
Nathan (Customer)
[00:06:44] yes
Madhu T (Tutor)
[00:06:48]
[00:07:00] Let me know if you need help taking the first step to finding k
Nathan (Customer)
[00:07:17] first would be to find LN 1,200,000?
Madhu T (Tutor)
[00:07:33] Not quite.
Nathan (Customer)
[00:07:44] yeah, I forgot to divide by 400,000
Madhu T (Tutor)
[00:07:46] It is only once we have the 'e' isolated, that we start to look at ln
[00:07:48] There we go!
Nathan (Customer)
[00:08:45] correct?
Madhu T (Tutor)
[00:09:02] Looks good so far! I would suggest keeping that full value of LN(3) in your calc
[00:09:09] And using the long decimal, for best accuracy
[00:09:30] k =
Nathan (Customer)
[00:09:50] right?
Madhu T (Tutor)
[00:10:02] I got k = 0.3662, not rounding any where in between
[00:10:13] It depends on your teacher, how accurate they want you to be
Nathan (Customer)
[00:10:15] yep, I see where I messed up
[00:10:39] 3 decimal places
Madhu T (Tutor)
[00:10:44] Sounds good!
[00:10:52] And now, we are ready to get the answer for 8 days
[00:12:10] Excellent!
You did that step perfectly.
Nathan (Customer)
[00:14:08] correct?
Madhu T (Tutor)
[00:14:29] Your steps are good. However, the rounding in between caused our answers to vary
[00:14:38] I got 7,488,302
[00:14:51] Do the instructions say anything about rounding?
Nathan (Customer)
[00:15:00] I don't think I rounded
Madhu T (Tutor)
[00:15:13] That value of k is a long decimal number
Nathan (Customer)
[00:15:16] I did it all in one calculation on my calculator
[00:15:21] oh, I see
Madhu T (Tutor)
[00:15:26] If we use only k = 0.366, that right there is rounding
[00:15:35] But your method is perfect!
Nathan (Customer)
[00:15:43] Thanks!
Madhu T (Tutor)
[00:15:50] So as we wrap up, do you have questions about anything we covered today?
Nathan (Customer)
[00:16:12] no, that was very helpful!
Madhu T (Tutor)
[00:16:17] It was a pleasure working with you today!
[00:16:19] Would you please fill out the survey as we exit? Thanks so much! And bye for now
Nathan (Customer)
[00:16:19] thank you for your time!
[00:16:21] bye
[00:16:22] !
