#help-33
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And we correctly wrote this at some point
yes!
I don't get how we get that in cross multiplication at all ngl
It’s not working
Not sure what to do
why did you change? this was correct
ok, now that we finished this, it will be easier to answer each question
look at the right hand side here
try to find which right hand side fits the most
Middle one
(Cos^2(t) + sin^2(t))/sin(t)
I got it
There is a third part😭
I GOT IT
FINISHED IT
congrats!
I AM SO SORRY
For the hassle
It just wasn’t clicking
And i’m running off of like 3/4 hours of sleep
Can I get your help on another way easier problem
alright
@soft tangle bring it on
can you take a better pic pls?
great
Cool
Alrifht
Alright
So i’m trying to identify an identity i can sue on the first one
let's start with the first one
Ok
if you write $y = sec(x)$, the first expression writes itself as $\frac{4y^2 + 4y+1}{2y+1}$
rafilou2003
Ohhhh yeah
can you factor the numerator?
you can do a long division
No good???
Is that where you draw lines and then do something with the x’s
You know how to do polynomial division right?
I am rusty but I can easily remember
Can you help me tho
I don’t really remember it
Ok
Basically, in it's easiest form it's something like ax^2 + bx + c divided by x+d
We always start by getting rid of the highest term in x
So we have to get rid of ax²
So we take (ax²+bx+c) - ax(x+d) to get rid of all the x²
Then we're left with terms in x, so we have to get rid of them as well, etc...
This video tutorial explains how to perform long division of polynomials with remainder and with missing terms. It's explains how to do long division easily and it provides the step by step process to get it done. Basically, there are 3 steps that you have to repeat. 1. Divide 2. Multiply 3. Subtract This video contains plenty of ex...
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I get how they got this but
why does integrating from 0 to 2pi
and then dividing by 3
result in 2pi / 3?
cuz im thinking u can just find the total area of the 3 petals
and then divide by 3 to get one
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basically all i don’t get is like
why do u integrate from 0 to pi
and not 2pi
OH THE PERIOD FOR ODD PETALS IS PI
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yeah
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Integral of x*e^(x)^2
What form of integration is required and how do I approach
Have you tried substitution?
Yes
Hm? So it's $xe^{x^3}$?
A Lonely Bean
Correct
Me too lol
It would’ve been easy if it was to the power of 2
But 3makes it confusing
do you know gamma function?
this doesnt have closed form solution
What doesn’t?
the integral
You can try by parts apart from that it's not possible to integrate
Have you tried wolfram to check if it has a closed form?
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how i do this one?
!status
What step are you on?
1. I don't know where to begin
2. I have begun but got stuck midway
3. I got an answer but I'm told it's wrong
4. I got an answer and would like my work checked
5. I have a question about someone else's worked solution
6. None of the above
i forgot how to do limits and im trying to remember how to do them
multiply & divide by the conjugate
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when finding the radius of convergence and interval do u always use the ratio test?
where the lim n-> inf abs for an+1 / an?
and for the case of alternating series
does the absolute term get rid of (-1)^n?
like i can disregard it/consider as 1^n?
abs((-1)^n)=1 so yes you can just ignore that
well you use the ratio test when it works
sometimes it will be pretty impossible to calculate the limit you get
or you can do it and it gives 1, then you have to search for another test
so its like the convergence tests where it may become a case of trial and error with the alternating sreies, comparison, etc?
ratio test is a convergence test
do u have any tips on recognizing what tests i should use when testing for convergence in general?
ye i get that ratio is one of them
well if stuff will cancel from a_(n+1)/a_n then its probably a good start
classic example being eg factorials
ah ok
with time you get a bit of a feeling for what tests might work
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Hi. I actually asked how I could solve this same problem yesterday. However, I'm stuck in how I am supposed to find when does P = -1. The idea is to solve this only using high-school math, so thankfully someone can help me, not using modular arithmetic and that kind of stuff. Someone provided me an explanation that you could match up "mod" and arguments, but technically there is a way to solve these having 0 idea about modular arithmetic, or in general, more advanced math than the one that is taught in high-school. Maybe you need to use implicitly the concept of "mod" without knowing what does that mean? I am not sure. Anyways, as you can see, the explanation and the step by step doesn't have to be that rigorous. Thank you
Probably the exercise could led to the use of complex numbers, as the way taught in high-school (Euler identity and related I guess, not sure tho). Sorry if my English sounds kind of unusual. I am using a translator.
I just realized the multiplication by a vertex and its conjugate is equal to |z|^2, which is always a real positive number. Maybe there's one way to start solving the problem using that fact, somehow matching up the product of the moduli to be equal to 1. By inspection I could say that [ 1/2 times (√2)^2 ] ^ integer have always modulus 1, which would be equivalent to the product of V1, V4, V3 or V6 with (V2 or V5)^2. However, I'm not sure if this is the right way to proceed. I feel somehow you have to use the fact that the hexagon is centrally symmetric
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Differential equations. Im stuck
What step is next? I substituted y’ , but idk if thats right
Distribute y^2
I meant in your step 2 here
Oh you kinda did here. You forgot to square your whole x term
Where did the ^2 go in your y' here?
Ah, forgot it indeed
But im still stuck 😂
After substitution, I shouldnt have any y's left, Only x's and C's
Atleast, thats what my book says
!show
Show your work, and if possible, explain where you are stuck.
Can't really show much more than this ^
The book takes the derivative of the general solution (like I did), but solves it for y.y', and I solved it for y'
And I dont know when to solve for what
Or do I just guess and see
Show me your corrections
Distribute the y^2 now, yes
You'll be left with your original equation, which was given
So that suffices your proof
Ah so its correct too, okay
Much simpler than my book
What about finding a particular solution? Normally you just pick a value for C at random right?
Nvm, all checks out, thx
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how do i solve this i have no clue
Did you try multiplying and dividing by the conjugate
can you elaborate
"rationalize the numerator"
Multiply and divide with $\sqrt{x^2 - 2x} + \sqrt{x^2 + 2x}$
NEONPerseus
i mean -4x
I'll help you with the positive infinity part you'll be able to do the negative one by yourself
sure
$\lim_{x \to \infty} \frac{-4x}{\sqrt{x^2 - 2x} + \sqrt{x^2 + 2x}}$
NEONPerseus
@slow dock this is what you have right?
I might have to leave in a bit
So I'm just ask you to factor an x^2 out of each square root and cancel it from the numerator
That should land you with an answer
did you do as NEON instructed?
Looks almost done, just divide numerator and denominator by x
i did sqrt(x^2 -2x) + sqrt(x^2 +2x) = sqrt(x (x -2) + sqrt(x (x +2)
then i factor out sqrt(x)
oh, if want to take common, then take x^2 as common not x
can you explain
notice that $x = \sqrt{x^2}$
numbpy
If you have difficulty understanding taking common, then I suggest just dividing by x above and below
lemme give an example
$\sqrt{x^2 + x} = \sqrt{x^2 (1 + \frac1x)} = x \sqrt{1 + \frac1x}$
numbpy
does this help @slow dock
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divide numerator and denominator with k^1/3
My main issue is with the denim
Denominator**
After simplification, it would be k^(3/2)+k^(1/2)+sqrt(3)
Correct?
they should all be on the same square root instead of seperately
so the top goes to 1
the denominator is now
sqrt(k^3+4k+3)/k^(1/3)
is that correct?
yep now get it inside of the sqrt
wasnt that this tho
not even close to that
oh
how did you magically pull other stuff out of sqrt
anyway you shouldnt try to divide all of the stuff by k^1/3 , only divide k^3 by it since it has the highest power
distribute 1/k^3 in it
it should become 1/k^6 inside of the square root
my bad
1/k^2/3
correct?
yes
multiply the exponent by 2 while getting 1/k^1/3 inside of the sqrt so you get 1/k^2/3
dont u mean 1/2
?
cuz i thought sqrt of x = x^(1/2)
so wouldnt we multiply everything in the root by 1/2?
|x|=sqrt(x²)
this is not true for every x
right but for now the numerator of the denominator can be simplified as (k^3+4k+3)^1/2
no?
so highest variable in terms of k on the numerator is k^1/3 right, and on the numerator its k^3 but its in square root, if you eliminate every other terms it becomes k^3/2
you can just k^(1/3)/k^(3/2) then pick (bn) as that
that is very cursed you cant eliminate square root like that
oh you cant?
oops so then we can just use k^1/3 / k^3/2
ok i follow what you did here
sqrt(a).sqrt(b)= sqrt(a.b) so you are good now
mhm so you can multiply it right theough and get sqrt (k^3+4k+1)/sqrt(k^2/6)
2/6 instead of 2/5 and its right
highest term of k, after division inside of sqrt
which will be same as this
right
k^3/2 holds more power than k^1/3
so youd compare it with that correct?
huh?
my brain was lagging because im looking after my dog at the same time
yeah go on from there
lol
so after you evaluate that, take bn as that value
yeah
well if im being honest you dont need to evaluate, you can just take bn as that
and apply LCT
mhm
got it!
thanks so much for your help and patience lol
i appreciate it
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@thorny iris Has your question been resolved?
have you drawn a diagram yet?
@thorny iris Has your question been resolved?
yeah
hello?
it should be clear from your diagram
you're looking for the green length, you just find the angle from cosine
there's a right triangle
oh that's arccos
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how do i find the area for this
surround area or surround and surface?
no the area
That is a 3D object, it doesn't have an area
It has a volume, and it has a surface area
the surface area
Should be 2πrh+2πr^2
Please send a picture of your original question
it’s here
That is just a picture of a shape, it doesn't state a question
it said determine the area of the following solids
It did not say that, because solids don't have area
no
Surface area is just the area that makes up the outsides of a shape
for example if you take a simple cube
the surface area, is the area of all the square faces of that cube
ok
So what are the different faces on the cylinder that you sent
1 rectangle?
Where do you see a rectangle on the cylinder ? :o
what idk
If the surface area, like we said earlier, is the area of the faces that make up the outside of a shape, to find the surface area for the cylinder you have to identify what its faces are
For example, what shape is on top and bottom of the cylinder
those would be two of its faces
The top and bottom yes, just two circles
and then the only remaining face is the side of the cylinder
do you have any idea how you could find the area of that?
1x2.8 and 4x0.2
Hint: Imagine taking the cylinder and unrolling it so that the side becomes a rectangle, what would the base and height of this rectangle be? The base would be ||the length of the circumference of the top circle that we unrolled|| and the height would be ||the height of the cylinder|| So the area of this side of the cylinder, or the unraveled rectangle, would be ||circumfrence * height||
So now you have identified the 3 sides of the cylinder: 1. top circle 2. bottom circle 3. the side. To find the surface area, find the area of these 3 sides and add them up.
0.2x2.8?
what is circumference * height
The length of the circumference of the cylinder, multiplied by the height of the cylinder
Do you know what the circumference is?
the length is 2.8 and the height is 0.2?
No
The height of that cylinder is 2.8m, and the radius of that cylinder is 0.2m
Again I'll ask, do you what the circumference is?
no
The circumference is the length around the outside of the circle
Length of the circumference = 2 * pi * length of the radius
ok
So can you tell me what the 3 shapes are that we need to find the area of, in order to find the surface area of this cylinder?
what
The surface area is the area of all the sides of the shape. What are the 3 sides of this cylinder?
(we figured this out already earlier)
2 circles and 1 rectangle
Sort of, the rectangle isn't really a rectangle though right?
You recognize that it is just the curved side of the cylinder, yes or no?
yes
Okay perfect
So we need to find the area of the 2 circles, and the area of the "rectangle"
Do you know the formula for the area of a circle?
pie symbol and x2
AustinU
Does that seem familiar?
the dot is where the number goes in?
The dot is multiplication
What grade are you in?
8
Okay, well I can't continue to help you find the surface area of this cylinder if you are unable to find the area of a circle. It seems like you are missing a lot of background knowledge needed to solve this problem. I can direct you to a video to learn
Welcome to How to Find the Area of a Circle with Mr. J! Need help with finding the area of a circle? You're in the right place!
Whether you're just starting out, or need a quick refresher, this is the video for you if you're looking for how to calculate the area of a circle. Mr. J will go through area of a circle examples and explain the steps...
Welcome to How to Find the Surface Area of a Cylinder with Mr. J! Need help with finding the surface area of a cylinder? You're in the right place!
Whether you're just starting out, or need a quick refresher, this is the video for you if you're looking for help with cylinder surface area. Mr. J will go through calculating surface area examples ...
I'd watch both of those in order, and then you should be able to figure this out
It is 6 minutes long, and I sent it 1 minute ago, how have you already watched it?
nvm what do i do now
stop interrupting other people's channels, I directed you to read #❓how-to-get-help and #rules already
Watch the videos, otherwise I can't continue to help
i did
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Can anyone help me how subspace scalers are converted into matrixes
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ive tried everything but the most i can get is QR = asinB/2
i knw thatnearly all of these triangles are isoceles so BQ and QC have to equal a/2 im just not sure where to go from there or how cos gets squared
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sorry no one answered you
T-T
uh
i tried to big brain it out but now i have to go to school lol
oof
uhh
well you're working with an icoselies trangle
right?
do you have a diagram??
Ok
I mae it
you need to use the cos rule
and the sin rule
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Hello! this is calculus so i’m not fully sure if i’m allowed to post this here but anyone please just let me know but anyways i need to find this using L’Hôpital’s Rule and i’m stumped on it! Help is appreciated 😊
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just a quick question
when you have x^2-2x+8/9=0
can u multiply the whole equation by 9 to get rid of 8/9
Is that $\frac{x^2-2x+8}{9} = 0$ or $x^2-2x+ \frac{8}{9} = 0$?
?
dldh06
Yes you can multiply by 9 if you wanted to
note there’d also be a 9 in front of the two other terms
yes
Don't forget the = 0
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What step are you on?
1. I don't know where to begin
2. I have begun but got stuck midway
3. I got an answer but I'm told it's wrong
4. I got an answer and would like my work checked
5. I have a question about someone else's worked solution
6. None of the above
Show your work, and if possible, explain where you are stuck.
@twilit quiver Has your question been resolved?
@twilit quiver https://stattrek.com/estimation/confidence-interval-mean
How to construct a confidence interval around a sample mean. Includes sample problem with clear, step-by-step solution.
If you wanna show your work I might be able to see where you messed up
Probably something with alpha
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@twilit quiver Has your question been resolved?
Sorry I'm running errands, haven't looked yet
n = 25, N = 500
xbar = 25.7,
s = 7.8
I guess we have to do a correction factor since n is only 5% of N
fac = 1.5220227022657792307
I don’t get how u got this?
It's the formula on your page
I was just driving so I didn't multiply by the t value yet
p* = .995, df = n-1 =24
Using a t-table or calculator, that value is...
can I write the full working out pls if that’s okay
Oh, using df =24 and alpha = 1 - .99 = .01
I'll do that in a second if thus works
T-Value (right-tailed): 2.351635
T-Value (two-tailed): +/- 2.609228
https://goodcalculators.com/student-t-value-calculator/
© 2015-2023 goodcalculators.com
Use this T-Value Calculator to calculate the Student's t-value based on the significance level and the degrees of freedom
I think we want the two-tailed?
Multiply that by the fac
yes I think
lmao but look at the options
...which is not even close
If thr mean weight is 25.7g, how can we have a confidence interval for the "total weight of the population" that is between like 10 and 15? 🤨🤨🤨
OH!
uh oh
This is orders of magnitude larger
wdym
Multiply by 500/25?
umm
Doesn't seem like enough though
Or by 500
Yeah
Let's see
I don't have my scientific, what's the min if we do that?
I don’t get what u mean haha
Well...if we do that, the min is kinda close to the fourth option
Not very though
Not by scientific standards
Me neither
Because you don't show your formulas
You have the notes from the professor, amd I assume the values are supposed to match those
Yes
But you don't show the t-value computations
500(25.7+-2.351635)
crunch that really quick
Oh
and no
there seems to be a mistake in the question
I don't think it's the sample standard deviation, but rather the standard deviation of the sample mean
Yeah, my vocabulary is trash
For example, "fac" I was using is actually called "Standard Error" or SE
Everything after +- is the Error Margin (Margin of Error), ME
Can you show the critical value computation?
And was your df 499?
why is this related to a t distribution? am I missing something
Oh!
I was using the population size and not the sample size
df = n-1
Not N-1
Thank you
what does this have to do with a t-distribution though
It's part of the confidence interval formula?
not really
that's only if your estimator / test statistic is t-distributed
in this case, the sample mean is approximately normally distributed
and your estimate of the total weight is just the sample mean times 500 is it not?
I’m confused lol
the sample mean has a standard deviation of approximately 1.6, so if you multiply the whole thing by 500, I guess that gives you a whole thing standard deviation of 780
can someone work it out
a 99% confidence interval for a normal distribution is everything within 2.575829 standard deviations of the mean
and the mean of the estimate of the total weight is 500 * 25.7 = 12850
Where did you get 1.6?
They gave a sample standard deviation of 7.8
7.8 divided by sqrt(25)
We got the times 500 thing
or rather, an unbiased estimate of the variance of the weight of each individual item is 7.8^2, and the variance of the sample mean is 7.8^2/25
Ah.
hmm maybe you do have to take into account that the standard deviation is not perfectly estimated
but you can't really I think
or rather, it's annoying to do
Well there is that long bit that ^ @shell inlet has here
In the fomrula
The SE calculated differently b.c. the sample is <= 5% of the population size
...I think
well, suppose you consider the test statistic t = (sample mean - 25.7)/7.8 grams; maybe that's t-distributed
yeah but why would it be a t-distribution
the sample mean is assumed to be normally distributed
oh there's a finite population correction
Oh...
okay that makes sense
I used the wrong value
I get an answer similar to the last choice now
the uncorrected sample standard deviation is 7.8 grams, but applying the finite population correction, one gets an estimate of approx 7.61 grams for the population standard deviation
I still don't know why y'all are doing anything with a t distribution
Makes the rest work out as it does in OP's notes
why is anything t-distributed
🤷
hmm maybe it's because of the estimated standard deviation
yeah
that gives the second choice
okay it all makes sense now
so basically, we claim that the value (25.7 - true mean) / (7.8*FPC) is t-distributed, and then a 99% confidence interval for this is something; this lets you compute a confidence interval for the sample mean
and then if you multiply it by 500, you get the second answer
@twilit quiver Has your question been resolved?
wait can someone write out the working on paper step by step pls, I’m new to this
wait can someone write out the working on paper step by step pls, I’m new to this
I think the easiest way to explain this is probably by referencing your prof's slides
find a 99% CI for the sample mean
then just multiply the thing by 500
so you know the population mean is 0.5 and the population variance can be calculated as p(1-p)
yes
I used the zscore table to find the values and then I calculated it but I didn’t get the answer lol
can you elaborate more on what you did?
so I found the zscores that correspond to 0.05 since it’s symetrical then it is -1.65 and 1.65
So that one is the lower bound value
is the wrong?
@flat raft
Yea but the answer is wrong apparently lol
well it says four decimal places, so maybe you rounded a little early
actually at four decimal places, you might even have to do a continuity correction ew
I get 0.4418 with more exact arithmetic
but nah there's definitely a continuity correction here
wait what’s that again?
basically the sample percentage comes in multiples of 1/200 = 0.005
yep
so when you approximate the sample percentage with a normal
since it's a scaled binomial
you have to do some silly shit where you add 1/400 or something
idk how I would even answer this question without at least saying something about whether the limits are inclusive or exclusive
I'll just assume the limits are inclusive
ahh i see haha,, do u know how I would do the next missing blank
waitI can't actually see the entire question for that one
I think it's just 0.5 - lower limit
but it might also be asking for percentage error, in which case it's (0.5 - lower limit)/0.5
Can u explain why?
well if you say that it's contained within [lower limit, upper limit]
isn't that just the same thing as saying it's contained within (0.5-lower limit) of 0.5?
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If a is an integer and 7|4a, then 7|a.
Proof. Suppose a is an integer and 7|4a. That means 4a=7b for some integer b. The only way this is true is if they are both multiples of 28. Thus 4a=28c for some integer c. So a=7c, and 7|a, by definition of divisibility. |||
Is this proof valid?
"The only way this is true is if they are both multiples of 28"
Why?
They must be multiples of their lcm
Because they are coprime
That is not an axiom
Arguably that's by definition of the lcm
Otherwise it's an exercice in and of itself
You can just use that if p|a*b, then p|a or p|b, if p is a prime
And 7 doesn't divide 4 so it must divide a
yeah
so can I use this argument?
Depends on what you already know
@humble walrus Has your question been resolved?
If you know it you can use it no ?
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quick question: what do you write when an integral isn't continous betwenn two bornes?
Assuming it's defined (i.e. not going to infinity, otherwise it gets more tricky to say the least) and there's finitely many discontinuities, nothing special as integrals are naturally also defined for such functions
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hii
i have dirichlet function
and i have to say
if the functions below are continous and in what ranges
@near blade Has your question been resolved?
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hi
is there a way to prove these 2 smaller triangles created from that perpendicular are similar?
wait i just realized
that perpendicular line splits the original right angle into 2 angles
since that first angle is 90 the other 2 have to add up to 90
thanks that makes sense, is this true when you make a perpendicular to any right angle in a triangle?
this doens't
is that perpendicular going to the right angle
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A husband and wife 6km apart start walking towards each other. The husband walks at a speed of 4km per hour while the wife walks 3km per hour. A fly starts from the husbands forehead at the instant he starts walking and flies towards the wife towards the speed of 5km per hour. when it reaches the wife, it suddenly turns back and flies towards the husband. It continues to fly back and forth until the husband and wife meet. After that, what is the total distance the fly has flown?
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what are some examples of trivial isomorphism functions
like 2 groups are clearly the same, but I can't think of a function
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just a question
?
i mean i feel like i can solve any sides just with sine and tan
and just add pythagoreas theorem on some
You need the length of two sides, or the length of one side and the measure of an acute angle
what
you can use trig ratios to find missing sides
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I'm not sure how to proceed here
B(n) is bells number
Show equation 5.3
ive seen this b4
but forgot how to do it
and try using the formula for binomial coefficient in terms of factorials
me on exams
@thorny jungle
if you're still stuck, n is a constant with respect to the summation and you can do a substitution on i
KN
Im not sure how to produce (n+1)!
<@&286206848099549185>
Ok nvm that was so dumb
I think I got it
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where does two concentric circles have radical axis?
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Hello, how can I prove that the limit of this function as n goes to infinity is 1/sqrt(e)
$cos\left(\frac{1}{n}\right)^{n^2}$
Mathu_lmn
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x^2+3x-6=0
dont know what to do next
what stage are you at
I told you how to write the second term as a square
$(x+\frac{3}{2})^2-(\frac{\sqrt{33}}{2})^2=0$
kheerii
kheerii
yes I told u
wait
so
ohhh
so
(x+3/2)^2-(sqrt33/2)^2 = (x+3/2+sqrt33/2)(x+3/2-sqrt33/2)
correct
how do u do x+3/2+sqrt33/2
you don't need to
you got $(x+\frac{3+\sqrt{33}}{2})(x+\frac{3-\sqrt{33}}{2})=0$
kheerii
when a product is equal to 0, you need to consider each term to be equal to 0 one by one
I just combined the fractions
x+c = 0 means x=-c
so i get
the opposite
of each bracket
like for the first one
(-3+sqrt33/2)
and 2nd (3+sqrt33/2)
what about that
you just put a bracket around the whole expression
that doesn't help
$-3+\frac{\sqrt{33}}{2}$ is what you have written
brackets where
kheerii
you just reiterated what you wrote the previous time
(-3+sqrt33)/2
is what I expected
oh ok
but your second answer is wrong
which
.
nope
$x+\frac{3+\sqrt{33}}{2}=0\implies x=\frac{-3-\sqrt{33}}{2}$
kheerii
$x+\frac{3-\sqrt{33}}{2}=0\implies x=\frac{-3+\sqrt{33}}{2}$
kheerii
oh ok
try being easier to work with next time
what have I done
be obnoxious
i just didnt understnad
Entitled, don't answer questions we ask
maybe bcs I dont know the answer
do I leave it like that @lucid zenith
Those aren't excuses for being entitled or ignoring us
Hundreds of people ask questions here without being difficult
yes
you can't simplify the answers further
,calc (3+sqrt(33))/2
Result:
4.372281323269
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✅
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Can someone help me with this?
can't you just integrate it? u-sub with u = sin(x)
Its asking for integration?
To solve the initial value problem, we need to integrate the given differential equation with respect to t:
∫dy = ∫9t dt
y = (9/2)t^2 + C
where C is the constant of integration.
To find the value of C, we use the initial condition given for each problem:
A. y(0) = 6
6 = (9/2)(0)^2 + C
C = 6
Therefore, the solution to the initial value problem is:
y = (9/2)t^2 + 6
When t = 0, y = 6.
B. y(0) = 1
1 = (9/2)(0)^2 + C
C = 1
Therefore, the solution to the initial value problem is:
y = (9/2)t^2 + 1
When t = 0, y = 1.
i agree with that solution
and again, you were given y', the general solution is y. So you integrate y'
y= 6 and y=1?
y is a function of t
y(0) = 6 is evaluating the function y at the value t=0
so once you integrate, you get y = (some function of t) + c
knowing y(0) = 6 let's you solve what that constant of integration c is
I get it. 🙂
@wooden grotto Has your question been resolved?
Okay wait for this problem, I got part A: To solve the initial-value problem, we integrate both sides of the differential equation with respect to t:
∫dy = ∫e^(9t) dt
y = (1/9)e^(9t) + C
where C is the constant of integration.
To find the value of C, we use the initial condition y(0) = 5:
y(0) = (1/9)e^(9*0) + C = 5
Simplifying, we get:
C = 5 - (1/9) = 44/9
Therefore, the solution to the initial-value problem is:
y = (1/9)e^(9t) + 44/9...but im getting b wrong..
To find the time at which y increases to 100, we can set y = 100 in the solution we found:
100 = (1/9)e^(9t) + 44/9
Subtracting 44/9 from both sides and multiplying by 9, we get:
56 = e^(9t)
Taking the natural logarithm of both sides, we get:
ln(56) = 9t
Solving for t, we get:
t = (1/9)ln(56) ≈ 0.7985
Therefore, y increases to 100 at approximately t = 0.7985.
To find the time at which y drops to 1, we can set y = 1 in the solution we found:
1 = (1/9)e^(9t) + 44/9
Subtracting 44/9 from both sides and multiplying by 9, we get:
-35 = e^(9t)
Taking the natural logarithm of both sides, we get:
ln(-35) = 9t, but that's not right answer....
<@&286206848099549185>
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