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anonymous
 one year ago
Currently have the first 3 answers here to start us off, not sure where to go from here, please help! (problems:
http://imgur.com/Eo8fZIR,mJ2vS04,3ys9vme,xyjbOve
) here's what i've got:
* A=40
* B=20
* C=12 hour period
anonymous
 one year ago
Currently have the first 3 answers here to start us off, not sure where to go from here, please help! (problems: http://imgur.com/Eo8fZIR,mJ2vS04,3ys9vme,xyjbOve ) here's what i've got: * A=40 * B=20 * C=12 hour period

This Question is Closed

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0What exactly is the question?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0There's multiple questions, would you like me to type them out for you? I don't mind.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Are there more than the 3 in the link? Or are you just asking if those answers are correct?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0There are more than 3, I have the first 3 which I listed and I need assistance with the rest, I believe the answers for the first 3 that I got are vital to answering the rest.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0There are 5 more questions, 2 bonus questions but i'm not too worried about them.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok. I didn't see the links to the other questions before

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh it's alright, you've got it or do I need to type them?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0For part d, a is the amplitude and b is 2π divided by the period The y = cos x parent function has a maximum on the yaxis. Your function has the minimum there, so make "a" negative

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so for A, the amplitude was either 40 or 20 from the previous questions, correct?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0The amplitude is 20, the answer from B

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I didn't have my work pulled up sorry about that, so it's y=20 cos 2pi x?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Wait! I read you wrong, a=20 and b=2pi/the period?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0close. you need to divide 2π by the period of 12 and make the amplitude negative to account for the reflection \[y=20\cos \frac{ 2\pi }{ 12 }x\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Am I going to need to get this down to one number for the answer to "a=" or will it be an equation?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Or will this be for both a= and b=

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0oh you're right. They are asking for a and b separately

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so a will be 20 and b will be π/6

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Does that make sense?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That does, I was wondering when the negative 20 would come in as I looked around online and saw that it would turn out like that, now the next question is to "sketch" and label a graph, Seeing as we can't really do that here, what would I put into my graphing calculator to figure this out?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Not sure if the draw option is any use, im new here

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0We could use this: https://www.desmos.com/calculator

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so you want to enter the equation we found above. and set your window to show 1 period at least

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so your horizontal axis should be from 0 to 12. and vertical from 20 to 20

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0y=20 cos 2pi/12x is the equation I want to put in?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Reduce the 2π/12 to π/6 and use parentheses to avoid ambiguity y=20 cos (pi/6)x

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Hold up, put everything after cos in (). y=20 cos ((pi/6)x)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Have this so far, should I fix it with the ()'s? http://imgur.com/ptftpkN

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0If I add the extra parenthesis it makes two lines, like this: http://imgur.com/KM6VOZB

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Is that what we want?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yes. If you zoom out you'll see the waves

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yes! alright so that's all that was? we're done graphing?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Mind sticking around and helping with the rest? I'll give you medals or whatever the currency on here is.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0oh yeah. I just meant we were done with that question

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Alright so F, how do we find the average water levels?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Just the top of the waves?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0It's the average of the maximum and minimum, which I think was 32 and 12. I need to go back to the beginning to check

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So what can we do with those to find the average? Divide?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Add them and then divide (52+12)/2 = 22

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Crazy how complicated they make it sound and then it's that easy! This next one may be a bit of a challenge

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I have the graph on hand, how do I determine where the times are?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That's where the first column comes in. 11:15 is 2 hours after 9:15, so you want to find y when x = 2.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0will finding y give the water level?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0not sure how to find it with just x, walk me through it?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yes. It might actually be easier to do this on a calculator than to use the graph. For the first one, plug in 2 for x. y = 20 cos ((π/6)*2) http://www.wolframalpha.com/input/?i=20+cos+%28%28%CF%80%2F6%29*x%29+at+x+%3D+2

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so for each one we just plug in the hours and we get the level, for this it's 10?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.03:45pm is 7 hours, right?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0and then 6:15 is 9 hours? I'm in high school I should really be able to tell time at this point but it's hard without a clock to look at.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0lol. It is 9. I'm just as pathetic. I have to count it on my fingers

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0wolfram just gave me the answer as "true", that cant be right

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0http://www.wolframalpha.com/input/?i=y+%3D+20+cos+%28%28%CF%80%2F6%29*9%29

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Just take out the y= so it will evaluate the expression

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0for the next one it's looking like we're working backwards, it gives us the water level but not the time, how do we manage this?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Use 7 for y and solve for x. 7 = 20 cos ((π/6)*x)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0http://www.wolframalpha.com/input/?i=7+%3D+20+cos+%28%28%CF%80%2F6%29*x%29?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0http://www.wolframalpha.com/input/?i=7+%3D+20+cos+%28%28%CF%80%2F6%29*x%29%2C+0%3Cx%3C12

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0sorry about that. You have to restrict the domain to just the period, or it will give all possilbe answers

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0this is looking like jibberish to me, is it 12? i'm seeing 12 a lot in there

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0hold up. can we go back to part c for a second?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0the 12 hour period, yes

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0The period is actually 24. (9:15 to 3:15 is only half the period)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.09:15 to 3:15 is a six hour gap. so six hours from low to high plus 6 hours from high back to low is a 12 hour period, right?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok. yes. massive brain fart

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so is H a 12 hour period as well?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yes, so there will be two solutions over the 12 hour period

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ignore all the "alternate form" gibberish and scroll down to where it says "solutions" You may have to click on the "approximate form" box http://www.wolframalpha.com/input/?i=7+%3D+20+cos+%28%28%CF%80%2F6%29*x%29%2C+0%3Cx%3C12

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Do you see x = 8.32 and x = 3.68?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I see them now yep, what do they have to do with it?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0no, they are the x values where the water level is 7

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0and they helped us determine that it's a 12 hour period in some way I guess?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0The other way around. The equation 7 = 20 cos ((π/6)*x) has infinitely many solutions. We used the 12 hour period to restrict the amount of solutions the equation would give us. That's why the 0<x<12 is in there

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So to find the times for H, add 3.68 hrs and 8.32 hrs to 9:15.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0not sure how to add .___ in time

anonymous
 one year ago
Best ResponseYou've already chosen the best response.09:15 is 9.25 hours 9.25 hrs + 3.68 hrs = 12.93 hr (pm) convert 0.93 hrs to minutes by multiplying by 60 → 55.8 minutes First time 12:56 pm

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0wait a minute are we still on H or have we moved onto the bonus questions? I'm getting lost in all these times here as I know 9am is involved in both

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I thought we were still on H

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I was showing you how to add the times.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0The first time we got for H was 3.68 hours. We need to add that to 9:15 to get the time of day the question is asking for

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0that makes much more sense, and when you did that you got 12.93, correct? should we round this?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0With 12.93, we have to convert the decimal part to minutes, because there's no 12:93 on a clock. That's why I multiplied 0.93 by 60 to get 55.8, and I rounded that to 56 minutes

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So it's only a 56 minute period?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.012:56 is the time at which the water level is 7

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0got it now, thanks for the description, it's okay if you dont want to do the bonus questions but if you're up for the challenge I am as well

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0If the low tide repeats every 12 hours, there will be 3 in a 24 hour period, inclusive. dw:1433136689393:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0and you can go off that same chart to get both? I'd think so since high and low are both on there

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Well I gave you best response which I guess gave medals, is there anything else I can give you? very thankful you stuck around to help

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0No I think that's it :)
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