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#101 Help Me ! » inversely proportional » 2021-12-08 17:05:08
- Hannibal lecter
- Replies: 1
A formula representing the statement “q is inversely proportional to the cube root of p and has a positive constant
of proportionality.
the answer was
but I thought the answer would be :-
q = 1/k * p^(1/3)
k is the constant
in book manual solution from where he got the "8" number?
#102 Re: Help Me ! » percentage growth vs actual growth meaning » 2021-12-08 11:20:15
hi Hannibal lecter
Part (a) asks about the percentage growth being positive. This is 2005 to 2006. You have understood that ok.
Part (b) asks about the actual price. That is where my extra row helps. Using my 'index' of 100 as the starting point you can see the price drops in 2004. But after that the price recovers and is above 100 for the rest of the years. So I think the answer to part (b) is 2005 to 2008.
Hope that helps,
Bob
you worked it very accurate and neat I like they way you work
do you think the book needed only intervals for each consecutive years because that it's ignored some values?
pls read the book full manual solution :
(a) The largest time interval was 2004–2006 since the percentage growth rate increased from −5.7 in 2004 to 9.7 in
2006. This means that from 2004 to 2006 the US price per watt of a solar panel grew relatively more with each
successive year.
(b) The largest time interval was 2005–2006 since the percentage growth rates were positive for each of these two
consecutive years. This means that the US price per watt of a solar panel steadily increased during the two year span
from 2005 to 2006, then decreased in 2007.
do you notice about "consecutive years"? I think the BookManual solution provider understand what the textbook wanted and he give it to him right?
because from what I see now both you and other answer looks acceptable expect your answer is more accurate
#103 Help Me ! » proportionality » 2021-12-08 10:57:20
- Hannibal lecter
- Replies: 1
Hi,
y = 2x + 1
the y is not directly proportional with x because the function is not like that : y=kx
because of number +1
my question is how this number "+1+ effected on these quantity that made them not proportional to each other
my second question is : I saw this image in mathIsFun site talking about proportions (https://www.mathsisfun.com/algebra/proportions.html)
from this image I can see the white dog head is 10 and the other brown dog head is 15
also the body of white dog is 20 and body of brown dog is 30 => 10/20 = 15/30
how cold they become equal?
how can I make these quantities equal and right "=" between them
I read a lot of that and it's useful to solve some problems like finding the percent... etc
but I still can't imagine how they are equal and how could we right "equality" between them
I mean look they are different sizes
I know if I multiply the two quantity by 2 for example they will get larger is equal the head will become 20 and the other head will become 30, it's like ratio between them, but I still can not imagine how can I write equal sign between them because one is bigger from another
#104 Re: Introductions » Hello please need help from math experts very necessary topic » 2021-12-08 05:16:45
thank you for the support
#105 Re: Help Me ! » percentage growth vs actual growth meaning » 2021-12-08 05:14:44
if I didn't understand this exercise 100% is that will effect on studying the next topic which is exponential functions
if I understand this 85% can I cross and go to another topic? the next topic will talk about exponential functions
can I start reading it or I have to complete these exercises and understand it 100% from all ways?
#106 Introductions » Hello please need help from math experts very necessary topic » 2021-12-07 05:15:10
- Hannibal lecter
- Replies: 4
Hello, If someone is ignorance and not smart enough and learning math very slow
should he leave learning math or should he keep going even if it slow?
because for example study a math book of 800 pages costs me 3 months
it's 3 months mines from my age it's a lot only 1 book should I change me dreams or should I keep going and do what I'm thinking about?
please tell me the truth without motivational speeches just say to me the truth I won't feel upset
#107 Re: Help Me ! » percentage growth vs actual growth meaning » 2021-12-07 05:11:35
You'd have to wait until the end of the year before you had all the data for that year so, thinking about it some more, the 2007 point is actually 31st December 2007.
Bob
I understand you completely and you helped me a lot in that specially when you told me about negative and positive growth
but there is still a problem in the question please check that another problem with same answers and you will notice the conflict
Solar panels are arrays of photovoltaic cells that convert
solar radiation into electricity. The table shows the annual percent change in the US price per watt of a solar
panel :
a)Find the largest time interval over which the percentage growth in the US price per watt of a solar panel
was an increasing function of time. Interpret what
increasing means, practically speaking, in this case.
(b) Find the largest time interval over which the actual
price per watt of a solar panel was an increasing
function of time. Interpret what increasing means,
practically speaking, in this case.
please see the "a" branch is completely clear and the book answer is clear, the answer is from (2004-2006)
the problem again is in the actual graph, the book solution is : 2005-2006
you told me to chose the positive growth intervals right? look I draw it on notebook and you can see there is positive interval that the book ignored please see my pictures :-
there is positive interval I highlighted it in blue pen, please tell me what is happening is the book wrong or I'm not good enough to understand great ideas like this one
now because I'm confused I have to re-ask my question what is the different between growth in branch "a" and growth in branch "b" I didn't see in webs something called " actual growth I searched a lot" do you have simple example in clear numbers because I understand most of such subjects in interactive way like (price in 2011 per watt for solar panel is 2$ after growth 30% it become $2.6... and so on I only understand it this way sometimes when things goes difficult when I see numbers become real things and represent real simple things in detailed I understand more,)
so I wish after you help me in this question and we done from it I wish next to make your own simple example to me with all detailed pls
#108 Help Me ! » percentage growth vs actual growth meaning » 2021-12-06 05:10:28
- Hannibal lecter
- Replies: 6
Hydroelectric power is electric power generated by the
force of moving water. Figure 1.15 shows6 the annual
percent growth in hydroelectric power consumption by
the US industrial sector between 2004 and 2009.
(a) Find the largest time interval over which the percentage growth in the US consumption of hydroelectric
power was a decreasing function of time. Interpret
what decreasing means, practically speaking, in this
case.
(b) Find the largest time interval over which the actual
US consumption of hydroelectric power was a decreasing function of time. Interpret what decreasing
means, practically speaking, in this case.
I know (a) answer is the percentage growth was a decreasing function from (2005 to 2007)
but in (b) the book solution said actual US consumption interval was (2004–2007)
what is the difference before I see the book solution I thought it's also (2005 to 2007) same answer!
it's being two days I'm thinking about that and I didn't get the key
how it's 2004 to 2007???!!! the consumption is increased from 2004 to 2005 then decreased from 2005 to 2007
so we shouldn't include 2004
#109 Re: Help Me ! » percentage point » 2021-12-06 03:23:41
Let's have another example. The boss of a small company announces that the company is doing so well that everybody is going to get a 10% pay rise. The workers think great! They were getting $200 a week. Now they'll get $220. That's an extra $20 to spend (I'll ignore Uncle Sam for now)
Bob
the increase here is 10% as mention because 10% of 200 is 20 that's a percent increase right
but what is the percentage point here?
#110 Re: Help Me ! » annual sea level (function of time question) » 2021-12-05 18:34:27
yes I mean 1983, I knew there is a mistake but wanted to make sure
#111 Re: Help Me ! » percentage point » 2021-12-05 11:29:30
in Wikipedia it said :
percentage point or percent point is the unit for the arithmetic difference of two percentages. For example, moving up from 40 percent to 44 percent is an increase of 4 percentage points, but a 10-percent increase in the quantity being measured
I notice it said " but a 10-percent increase in the quantity being measured"
is there a simple example to explain that in real life time
#112 Help Me ! » percentage point » 2021-12-05 10:23:30
- Hannibal lecter
- Replies: 4
Hi, I find in math is fun site on this link talking about percentage point :
https://www.mathsisfun.com/percentage-points.html
in start the site said :
Example: Your earnings per sale went from 4% to 5%
That is a rise of 1 Percentage Point
(But is a 25% rise in your earnings!)
but I didn't find an live example may you make to me an example
like I'm selling a laptop by 100$ or any small little example explain how I'll be earn rising 25%!
#113 Help Me ! » annual sea level (function of time question) » 2021-12-05 03:24:21
- Hannibal lecter
- Replies: 2
Table 1.4 shows the average annual sea level, S, in meters, in Aberdeen, Scotland,8 as a function of time, t,
measured in years before 2008
Q) In what year was the average sea level 7.019 meters?
6.957 meters?
I found in book solution this answer : Looking at the table, we see that the average annual sea level was 7.019 fifty years before 2008, or in the year 1958.
and the average sea level was 6.957 meters 125 years before 2008, or in 1883
but how is that I see on table is 25! and 2008-25 is = 1993
the solution is it's fifty years before 2008!
is there a mistake right?
#114 Re: Help Me ! » my last question this month I know I made you tired from me » 2021-12-05 03:18:51
every answers of you is very helpful thank you so much I'm just being reading carefully and in accurate way and slowly and understand it
all of your answers helped me since I'm in the forums but I just don't say "thanks" in a comments because I think you prefer to talk about the subject only no side talk only discussions on the topic that the user posted so I just say thanks inside my mind I said thank you without reply on comments if I didn't understand your answer I'll 100% tell you that in the comment I promise I'm honest
#115 Help Me ! » my last question this month I know I made you tired from me » 2021-12-04 14:09:31
- Hannibal lecter
- Replies: 2
I'll provide answers for this question I have the answer but I have a question about the last section
please this question is very necessary for me and it's very silly in the same way
Residents of the town of Maple Grove who are connected
to the municipal water supply are billed a fixed amount
monthly plus a charge for each cubic foot of water used.
A household using 1000 cubic feet was billed $40, while
one using 1600 cubic feet was billed $55.
(a) What is the charge per cubic foot? answer : = $0.025/cu. ft
(b) Write an equation for the total cost of a resident’s Answer : c = b + 0.025w, b = 15, thus : c = 15 + 0.025w,
water as a function of cubic feet of water used.
(c) How many cubic feet of water used would lead to a
bill of $100? Answer of b section is : We need to solve the equation 100 = 15 + 0.025w, which yields w = 3400. It costs $100 to use 3400 cubic feet of
water
the manual solution of section b is confusing me.. I mean I can solve 100 question like that but without understanding it mentally
how to understand this mentally?
he put $100 = $15 + 0.025w
the solution of section a and section b is very easy and I know them
but the last section (b) is confusing me, in which law he put 100 dollar on the left and the other quantity (15 + 0.025w) to find how many cubic feet of water leads to 100$
what is that called in algebra, if you refer me to a link I will open it but I will not understand I need your own answer please if anyone know to to tell me that in easy way
I mean it's interactive math and interactive question, I need interactive answer too not just put 100 and solve the equation and find the cost, I can solve a lot of this question in future but someday I'll forget how to solve it! because I don't have the concepts in my mind and I don't understand this mentally
#116 Help Me ! » intersect of two lines » 2021-12-02 12:39:55
- Hannibal lecter
- Replies: 1
how to check if the lines is has intersect point or not without graph just from numbers and quations!
for example for these lines
c1= 40 + 0.15m
c2 = 50 + 0.10m
I know I do c1=c2 and intersect point is 200
but what if the lines are not intersected what result I'll get?
#117 Help Me ! » simple linear formula problem » 2021-12-02 12:00:27
- Hannibal lecter
- Replies: 1
A company rents cars at $40 a day and 15 cents a mile.
Its competitor’s cars are $50 a day and 10 cents a mile.
a) For each company, give a formula for the cost of
renting a car for a day as a function of the distance
traveled
answer :
C1(m) = 40 + 0.15m
C2(m) = 50 + 0.10m
I don't understand why the vertical intercept is 40 in formula c1 and c2
the company rent 15 cents a mile
and the other 10 cents a mile
so as a graph it should start from zero
what is the meaning of $40 and $50 here?
is it the value of you rent the car without miles? or what
the $40 and $50 is vertical intercept for the equation this prices is for rent a car of a day so it's a relationship between cost and days not cost and distance?
#118 Help Me ! » what is Straight-line depreciation? » 2021-12-01 04:14:28
- Hannibal lecter
- Replies: 1
what is Straight-line depreciation?
just a concept not a graph I read books and I pass through this term
I read about money being dropped or value is reduced???!
what is this is there a very simple example to explain that for me please
#119 Maths Is Fun - Suggestions and Comments » complex site » 2021-11-30 12:12:33
- Hannibal lecter
- Replies: 3
I can't use symboles here they are very complicated please use Microsoft math solver or any new way
like I want to copy the equation from another site and past it here! very easy from uploading it as a picture!! please
#120 Help Me ! » monthly waste collection charge » 2021-11-30 09:50:45
- Hannibal lecter
- Replies: 1
government charge $8 for each 32 gallon and $12.32 for 68 gallon how to calculate the dollar for each 1 galloon
I understand it's =
(12.32−8)/(68 − 32) = 0.12 dollars per gallon but can you please illustrate that how? because if I didn't find the answer of that I wouldn't solve it myself never, don't talk to me about slope and linear equations please, what is the relationship between the government charge $8 for each 32 gallon and the government charge 12.32$ for 68 galloon how could the book determine the dollar per galloon like that
because before I see the solution ... I did that ( don't laugh I know it's silly but I want you to check how I solve it) :
I simply divide 8/32 = 0.25 dollar each gallon
please
#121 Help Me ! » Find equations for the lines through the point » 2021-07-20 02:15:13
- Hannibal lecter
- Replies: 2
Find equations for the lines through the point (1, 5) that
are parallel to and perpendicular to the line with equation
y + 4x = 7
can lines be parallel to and perpendicular to at same time? I just didn't understand what is the meaning of ( parallel to and perpendicular to )
#122 Help Me ! » Find an equation for the line with slope m through the point (a, c) » 2021-07-20 00:58:10
- Hannibal lecter
- Replies: 2
Find an equation for the line with slope m through the point (a, c)
the solution is y − c = m(x − a)
but how cold that be graphically?
#123 Help Me ! » how to divide 3/7.5 » 2021-07-20 00:43:01
- Hannibal lecter
- Replies: 2
Hi, how to divide 3/7.5
I know the solution is 2/5
but how is that by steps
#124 Maths Is Fun - Suggestions and Comments » this website is hard to use » 2020-07-18 00:40:00
- Hannibal lecter
- Replies: 3
Hi, can you please update this website? make it easy to write math input equations use multiples away options
and make easy to copy and past an image here please no need to upload a link just copy/past the image is easier
can you do this two things please to this site? and can you use an IOS and Android app for this site?
#125 Re: Help Me ! » How to estimate a derivative from a graph » 2019-10-23 09:21:18
I didn't understand
how did you exactly calculate these
isn't -1 = a -b + c (3) should be -1 = - a -b + c (3)
I mean the a is negative ? because you put -1
and what if it was not quadratic functions what you gonna do?
like :-
sol :
