#help-19
1 messages · Page 62 of 1
I think yes
no
Try to calculate the area of the function x^3 from 0 to 3
And then calculate the are of 6x from 0 to 3
and take the 2nd one from the 1st one
you wont get 6.75
yea -6.75 mb
It says area cant have both positive and negative values
How can I tell if it does or doesn’t
Without graphing it
Is there a way
Or does negative answer = difference of area
??
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Help with this. Am I doing this right?
.close
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had a question: how many points are required to strictly define an exponential curve?
can you do so with only 3 points?
wait, is the base known or not?
an exponential should result in some form of straight line
do you know if it is base e for example
base unknown
no
for context, i'm working on a numerical solver for the basic poisson equation (fluid mechanics)
i'm trying to reduce error, and i have 3 points that I know definitely converge to a correct answer
they form a straight line on a log-log plot (does the base matter in this case? i happen to be using base e) edit: shouldn't matter on second thought
and i'm trying to find the point which they converge to
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Can someone walk me through this problem?
The things I've written down are what I know so far
yeah assuming it's sinusoidal it will have an amplitude of 2000
we have to exclude the negatives though of course so you would need to take the absolute value
something like $2000\abs{\m\cos x}$ as a preliminary version is a good start
then you have to adjust the period for the fluctuations
what do you think so far? @subtle sleet
yes that makes sense, so right now we're unsure of how much fluctuation would occur
yeah ok
also to note i've forgtten the notation for how to do transformations on functions
[0.6\textwidth]
so the period of a sinusoidal wave is represented by $\f{2\pi}{\abs B}$ in $A\m\cos{Bx + C} + K$
thats fine
so like
how much should the period be from what you wrote?
entire time this is happening is over 21 days?
solve for B
read this
sorry still slightly confused
ummm sorry again i do not understand, do you mind like explaining this expression?
it's just the general shape of any cos
like
ANY cos function is of that shape
3cos(4x + 23) - 5
for example
thats just meant to describe the general shape of a cos function
im using it to explain how to find the period of a cos function
ok
ok i understand now that
great
so using this what is ur cos
B = 0.299 and that we multiply with x stretching the graph?
no
dont approximate it
but yeah the graph stretches with the multiplication
,w plot 2000|cos(2pi/21 x)| from -50 to 50
so cos (2π/21*x)
hmmm
maybe you should say for t > 0 but idk about 21
they never mention it stops at 21
it just fluctuates
although
wait
oh i see
this is not correct completely still
the period is a bit skewed because of the uh
absolute value
yeah
the abs(cos(x)) function has a periodicity of pi
instead of 2pi with the normal case
so here we replace 2pi witj pi
and we get like
,w plot 2000|cos(pi/21 x)| from -50 to 50
which now is accurate
yeah thats the word
but yeah it defines the range as well
multiply it by a number and that's how big the thing extends to
and you calculate amplitiude by max-min/ by something?
yeah
but because we are considering abs(cos(x)) instead of normal cos(x) in reality you calculate it as
A = max - min
because half the thing gets cut off (the negative portion)
max is 2000 and minimum is 0
so 2000
hmmmm
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how do you take the dot product if you don't have the angle between them?
you can compute the dot product from the components
so if you have 2 vectors
(a, b, c) and (x, y, z) then the dot product is ax + by + cz
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Guys, when he gets rid of the logarithm, how did he do it? What does he mean by raise 2 to each side?
In other words, the definition of logarithm base 2 of x is as the number you need to take 2 to the power of to get x
So $2^{\log_2(25-x)}=25-x$ by definition
Edward II
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I need a hint on how to do
\begin{align*}
\int e^{\sqrt{x}} , dx
\end{align*}
Substitution probably is the way, but I can't find the one. If we put $\sqrt{x}$ under the differential, we will have to multiply the expression by $2\sqrt{x}$ to counteract the $$(\sqrt{x})'=\frac{1}{2\sqrt{x}}$$
Sweet Tea 🧋
So it becomes
$$
2 \int \sqrt{x} \cdot e^{\sqrt{x}} , d(\sqrt{x})
$$
Sweet Tea 🧋
I.e. $$2 \int t e^t , dt$$
Sweet Tea 🧋
hmmmm, just a sec
Hello my friend
use integration by parts
,w (2 e^(sqrt(x))(sqrt(x)-1))'
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Somebody help pls
1/2 * height * base area
Do you know if the other ones are correct
lol
Retaking it
Do you know what it is
think you might be supposed to do this on your own
There’s options in the photo
<@&268886789983436800>
yea and retakes still count as tests lol
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Going through an old textbook and working out all of the math problems, I encountered this particular problem that I cannot seem to get the correct answer to. The answer in green is the answer in the back of the textbook. The text in red is how I originally approached the problem incorrectly. The text in blue is how I tried to reason how out how to approach the problem. The text in black is my work solving the problem which still resulted in an incorrect solution. Could someone point out what I'm doing incorrectly.
Is there a reason you have 16 - y as opposed to a second y in your integrand?
That seems to be the only difference
The 16-y is how I accounted for the distance to move each volume of liquid.
From y=0, the distance would be 16-0 = 16.
I think you may be right
At y=16, the distance would be 16-16 = 0.
I think that reasoning is right
I think 16-y here instead of y is correct, since you're pumping the water from wherever its height is in the tank to the top (y = 16)
well we are pumping water out of the tank. that means the distance should be 0 for y=0 shouldn't it?
unless there's a spout length i didnt see
The question states that I am pumping water to the top of the tank.
if its full though, wouldn't the water already be at the top and take less work?
oh i see whats going on
we are pumping from the bottom
The difference between my solution and the answer in the back of the book is a factor of 625/4 which seems too coincidental with F_v_1 = 625pi that I got in the text in blue.
,calc 21446605.85 * 4/625
Result:
1.3725827744e+5
Which is the answer in green.
if we are pumping from the bottom at all times, why would the height we move change?
16-y seems off to me
These types of early calculus problems generally aren't concerned with "reality". 🙂
They just want to know how you would calculate moving the entire volume of water.
But you are correct. In reality you would calculate the water pressure at the bottom at any given time and how it affected pumping water to the top.
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hey so I wanted to calculate which are my two lowest and most negatively impacting grades
but I don't know how to do it
compute (numerical score x % of total grade) for each exam or score or whatever
whichever two are smallest are the ones
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is there any formula for a finite set to know how many equivalent relations and clasees?
suppose set is given {4,5,6}
or I have to go through general way?
Every equivalence relation is the same as a partition of the set
So for example,
{4},{5,6}
is a partition and an equivalence relation
Sterling's numbers of second kind count partitions of fixed size of a finite set
It does not have a closed form unfortunately
In mathematics, a partition of a set is a grouping of its elements into non-empty subsets, in such a way that every element is included in exactly one subset.
Every equivalence relation on a set defines a partition of this set, and every partition defines an equivalence relation. A set equipped with an equivalence relation or a partition is some...
Like Kaynex said, there exists a one-to-one correspondence between equivalence relation of a set and its partitions
And it will be better to count the partitions of {4, 5, 6}
yes it will be
i count them and make partion
and i always tried the formula
thank you
.clse
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$(sin^2(x))^2 \leq sin^2(x)$
ColdTee
Is this true for all values of x
So this will be true for all values of x right
.
$0 \leq \sin^2(x) \leq 1 \
(\sin^2(x))^2 \leq \sin^2(x)$
ColdTee
Is this correct
Yes it's true for all x
That's what I was confused about since whatever value of x sin^2(x) will lie in [0,1] is that right
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@cold musk Has your question been resolved?
Yep
Ok so I see two ways to solve that
Mhm
You started this with a proof by induction right?
Yep
But your proof should have been done on un+1=2^n-1 ...
You prove that left side of equality is equal to second side
yep but idk why it switches from r to n
It's just letters dont be bothered by it
okay
The important thing is that they are integers
Mhm
Ok so start again
Is that step right or-?
That's right, though I would have written this in two parts. First the left hand side with u1 +1 (barely nothing to do) and the second with 2^(1-1) (u1+1) = 1 x (u1+1)= u1+1
But isnt the lhs subbing r and the other subbing n
And before it i said i was subbing just n for 1 or do i say r equals 1 for the other
I dont understand what you mean
r=n
Ohh
Substitute it by n
It's just a letter 🙂
Could have been m, p, or whatever
provided it is a natural number
But as I said you must do a proof by induction on the second highlighted equality assuming the first highlighted equality is true.
You dont need that equation for now
So i dont sub 1 for the left equation?
You will need it in the second part of induction
Because for induction when u prove the base case doesnt it have to be true and then u assume further and then the plus one
Dont need that equation haha trust me
ah okay
Is there latex here?
So the next part i assume true for P(k)?
and then i rewrite it with k instead of r and n
Your P(n) is actually $u_{n+1}=2^{n+1}(u_1+1)$
tresbienmonsieur
Yeah i wrote that first sentence
In your base case you must prove that the left side of equality is equal to right side
Then second part is your assume that for some k P(k) is true
So $u_{k+1}=2^{k+1}(u_1+1)$
tresbienmonsieur
Is true
I dont rlly get what u mean do u mind writing the first few lines so i hv an idea?
So do you agree with what I said?
Im just trying to make clear everythings so we are on the same page
So ur saying that the left side is equal to the right side
Thats what you must prove yes
But isnt the rhs power k+1 not k-1
I meant other way around sorry
You must prove P(k+1) is true now $u_{k+2}=2^{k+2}(u_1+1)$
tresbienmonsieur
But i thought it would be minus 1 for the other part
Bc if u sub n as 1
Im at this part
What was the other way with the geometric sequences?
P(1) is not good you must not use the equaton with r
Just the equation with n
Because its P(n)
The induction must be done with the equation containing n
Do you see what I mean? How did I lose you 😅
Im so sorry I must have brought confusions to you the rhs is 2^k and not k+1 since it was k-1
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Can there be a square matrix A, that has only right inverse?
eg.: AX=In but XA doesnt equal In
i dont thin kso
but why?
<@&286206848099549185>
I got it, since A is square and has right inverse, it implies that no rows are 0 in row echolen form of A, since A is square, all colums of A are basis columns, therefore A has left inverse.
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Prove that in a triangle, $\frac1{a}+\frac1{b}+\frac1{c}\le\frac1{a+b-c}+\frac1{a-b+c}+\frac1{-a+b+c}$
kheerii
We get $\frac{\sum ab}{abc}\le \frac1{2} \sum \frac1{s-a}$
kheerii
oh come on man not now
I know, I thought it got fixed by now
yeah seems like their fix didn't work or something
can you understand what I am trying to say though?
maybe I should refresh who knows
well I see your question yes, do I have any interesting idea about it not really
ok I will keep typing what I've got so far lmao
$\frac{\sum ab}{abc}\le \frac{\sum (s-a)(s-b)}{2(s-a)(s-b)(s-c)}$
kheerii
the sum on the right hand side numerator becomes $\sum (s-a)(s-b)=\sum s^2 - s\sum (a+b) +\sum ab = \sum ab - s^2$ (since $\sum (a+b)=4s)$
kheerii
and we have $s^2=\frac{\sum a^2 + 2\sum ab}{9} \ge \frac{\sum ab}{3}$, so the inequality left to prove becomes $\frac{\sum ab}{abc}\le \frac{\sum ab}{3(s-a)(s-b)(s-c)}$
kheerii
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After this I get $3(s-a)(s-b)(s-c)\le abc$ or $\frac{3}{4}r\le R$
kheerii
This is not even close to the optimal inequality (which would be 2r<=R), so I am certain I have made a mistake somewhere
@violet breach can you help now?
oops wrong person
@echo ginkgo
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But it still holds
Yes, but equality never holds
Ah
while it holds in the original inequality for an equilateral triangle
I should've gotten 2r<=R
Yeah hmm
do you see a problem somewhere?
Shouldn’t the second expression have denominator 4?
kheerii
No
$\frac{\sum ab - s^2}{2}\le \frac{\frac{2}{3} \sum ab}{2}$
kheerii
s^2=…/4
no?
Instead of 9
Np
god that took too long to figure out
Silly mistakes are hard to identify in so much alg
Hopefully, try it
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actually @supple mural Do you know of a proof of 2r<=R?
that doesn't rely on the formula for exradii
Not off the top of my head
hmm
https://www.ias.ac.in/article/fulltext/reso/020/01/0075-0075 this is the only proof I am aware of
but I wish not to use exradii formulas
OI as in circumcenter-incenter?
Yes
yeah, $\sqrt{R^2-r^2}$ right?
kheerii
Not quite
Yeah
ahhhh right
R>0
simple
The proof for it iirc comes from power of a point
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Consider the power of I wrt the Circumcircle
yeah that's what I was thinking
should be pretty straightforward
Yeah
maybe even cosine rule might work
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I am confused about this question
I know you need to find a left and right inverse, for the bijection
but in the answers, it defines the function g: [n + 1] -> X u {a}
where g(k) = {f(x) if k < n and a if k = n}
wouldnt it be a if k > n tho?
thats the part that confuses me
because if k = n, then it is still in X since [n] maps to X
I feel like this is not surjective if k = n part
because what would map to n, if k = n then k is {a}
anything else maps to an element less than n
the answer couldn't decide to use n+1 or <= and >
lol yeah sorry f(k)
were my supsicions correct then?
yeah, its a bijection, so i guess [n] and X f: [n] -> X since n is the same cardinality of X
Yeah but maybe by [n] they mean {0, 1, ..., n-1}
Well, one of these things is wrong
because 0 in N in my class
i mean it makes sense since a set is finite if there is a bijection from a subset of the natural numbers, which means 0 in [n]
That's irrelevant
what do you suppose?
Wikipedia uses {1, ..., n}
https://en.wikipedia.org/wiki/Enumeration
What would 0 map to then?
I can't say, I'm not your teacher, but I guess it's better to hold the definitions as true and assume the given solution has a typo or something
i mean would the + 1 be to map to 0 by definition of how enumeration is from {1, ..., n}
oh shoo
then you would have to fix the function definition
Well it says "initial segment {1, ..., n}" so in that particular article N does not include 0
to account for that
asking something that isn't in your domain maps to what in a function 
i guess undefined
no, 0 in my class is in N
oh that's terrible
and if it is undefined, then that function is not valid to use because the domain is undefined
I hate this class dont worry
but doesn't it impose 1 <= k <= n in your set construction
so 0 isn't in your enumeration anyway
Yes it doesn't matter whether N includes 0 or not, what matters is how they define [n]
They could've said [n] = {k in N | 3 <= k < n+3}, it would still work
(I mean the given solution wouldn't, but it already doesn't)
lets assume its 0 to n
i mean like, if n includes 0, wouldnt that mean that its basically the same idea but you use <= and then > to handle a
That would include n+1 elements
{0, 1, 2} is three elements
So 1 to n, like here
but f(k) implies that 0 is in X right
iim just trying to understand how this is surjective
f(k) doesn't imply anything
For f(k) to be defined, k must be in the domain of f, which is [n] = {k in N | 1 <= k <= n}
So that just means 1 <= k <= n
i feel like, something here is defined wrong for me
because 0 is a natural number, if n is defined that way, then 0 is never mapped to
and alos [n] -> [n] is bijective
0 doesn't have to be mapped
You can have a bijection between {3, 7655, 32411} and {t, w, g}
No 0 here
yes, but what if 0 in X but 0 not in [n] by the way n is defined
that's the stupid thing with your course treating 0 as being in N for some insane reason
by construction 0 is not in [n]
It doesn't matter
What elements X contains doesn't matter, only how many elements it contains
It could contain something other than numbers
oh, i understand
i guess this is why n has to start at 1 right
but then what is the size of the empty set...
they said size is defined by f:[n] -> X for some x
the logical answer
yeah it should be 0, but if n starts at 1, how is that possible
sorry im not trying to be difficult, im genuinely confused
recall the definition of enumeration
since n = 0 there is no k satisfying 1 <= k <= 0
so what's [n] when n=0?
I guess empty?
ye, so your f maps from empty set to empty set
That may be how to compare sizes (or really "cardinality"), but I don't think that's a good definition of size...
Is there a more clear definition that you think would be helpful?
Yeah, like we said earlier, either the definition or the solution is wrong
Well ok I may be nitpicking but I'd just define the cardinality of the set {k in N | 1 <= k <= n} to be n, and then you can compare that to the cardinality of X by constructing a bijection
("Formal definition" in particular, but it's a little complicated)
could you still use the same function definition idea, but like change the signs
so that f(k) = a if k > n
so for the + 1 case
Hey y’all I need help with a geometry analytic problem…
@late dust
Not sure what you mean
I want to find a correct bijection
g(k) = {f(k) if k <= n and a if k = n+1}

thank you for helping
could i also ask about part b)
actually nvm
thanks again
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4C
why is it leq
\begin{left}
\sum K(xi-x{i-1})(xi-x{i-1}) \
\leq\sum \textcolor{red}{ K\delta } (xi-x{i-1})
\leq \textcolor{red}{ K\delta}\sum (xi-x{i-1})
\leq K\delta (1-0)
=K\delta
\end{left}
4C
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
.close
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,plot |x|
graphically, why is the derivative at x=0 undefined ??
cause if we take a little nudge in the x direction, the function increases ? so it is defined ?
because the left hand and right hand derivatives are different at x = 0
which direction
isn't always from left to right meaning at x=0+epsilon
you need to have the left and right hand derivatives be equal for the derivative to be defined
i mean the derivative tells us if the value of f increases then f increases/decreases right ?
why do we care about left hand derivative ?
that's just how it's defined man
and the derivative does not directly tell us the monotonicity of the function
Norbert Baudin
the function does not have to be differentiatiable or even continuous to be increasing
yeah ik that
in this video, the guy defines the derivative as nudging the input x in the direction from left to right only
https://youtu.be/AXqhWeUEtQU?t=645
Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now: https://www.khanacademy.org/math/multivariable-calculus/multivariable-derivatives/partial-derivatives/v/partial-derivatives-introduction
Partial derivatives tell you how a multivariable function changes as you tweak just one of the variables in its inp...
timestamp 10:40
"nudging the input in some direction"
doesn't specify left to right
That's a representation
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Can someone clarify the definition of contably infinite for me
A simple definition of countable infinity is that it can be mapped with natural numbers
you can count it but it is infinite?
If we can defined each value of it using natural number or any other defined countable infinity without missing anything from its set.
You can watch the video on how rational number between 0 and 1 are more than natural numbers it will help you build the insight about it.
@mystic saffron Has your question been resolved?
You can't count, but u can find nth element or map it to some set
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I don't understand what you mean , sorry can you explain it more for me since I dont learn in english
Yes. And now you have 81^x = (something you can calculate)
what to do with the right side of the equation
am I suppose to it with a calculator at this point in the exam
I'd like to simplify it
Then rewrite all the negative exponents as fractions
No, 1/3^2
oh
I dont really know how to solve this without a calculator
First, the 1/3^2 on the numerator is really just multiplying the denominator by 3^2
I threw it in a calculator it says 3^(4x) = 3
So you can distribute that in
I dont understand this line of text
and then how do you continue?
Distribute the 3^2 in the denominator
like this?
Yes
but the answer shoulsbe x = 1/4
which is what I got in the calculator
oh I forgot this
this?
and 4/(4/3) = 3 ?
Yes
this makes my brain, and thanks 👍
Then you can just compare the exponents on the left and right side of the equation to get x=1/4
yep
I wish I didn't need to these kinds of equations for my studies honestly
takes a lot out of me
thanks a lot
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why can they turn this into a product of two integrals
shouldnt it be int ( (cos th + sin th) int (3r^2) dr ) d th
$\int_2^3 3r^2 \dd{r}$ is a constant
ℝαμΩℕωⅤ
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does anyone know how to factor this? a⁴ + 4a³ - 5
according to my book this is the factorization: (a + 1)(a - 1)(a² + 5)
but I don't know how he did to get to that expression
the first thought if you're supposed to factor polynomials is to look at (a + 1) and (a - 1)
at least thats what ive been taught when i had to do it

Try to guess easy roots like 1 and -1, it helps a lot.
If not then I guess you can resort to Rational Root Theorem
what I am having trouble seeing is what amount to add and subtract to make the right perfect square trinomial appear and then make a common factor or a difference of squares appear
should be able to do it just using common factor, common factor in groups, difference of squares, etc
I would first look at the powers, it tells you how many "a's" you would need in total, in this case its four so the possibilities are:
(a +- ?)(a +- ?)(a +- ?)(a +- ?),
(a +- ?)(a +- )(a^2 +- ?),
(a^2 +- ?)(a^2 +- ?),
(a +- ?)(a^3 +- ?)
sorry, the degree of the function
the next is to look at the next powers after the degree, which is just 3, which is not possible in:
(a +- ?)(a^3 +- ?) or
(a^2 +- )(a^2 +- )
so you know the function would look like:
(a +- ?)(a +- ?)(a +- ?)(a +- ?) or
(a +- ?)(a +- )(a^2 +- ?)
then you look at the numbers and go from there
hmm, why is not possible in that cases?
factor them out and see
it might be possible in the first one, nvm
but a^2 and a^2
it isn't
(a^4 + ?a^2 + ?a^2 + ?)
I guess there are 3 possibilities
it's possible
oh, so I was right the first time?
not possible
yeah, now try the other two that are possibile solutions
i keep having this problem
i tried a few numbers but got nowhere
I mean as they said, look at -1 and +1 first, if you get 0 then you know the (x +- ?) will be the +1 or -1
the basic (x +- ?) will be roots of the function
a⁴ + 2a² + 1 - 1 - 2a² + 4a³ - 5
?
what are you doing here?
trying to make (a² + 1)² appear
I just added and subtracted an amount to make the trinomial appear, but I didn't come up with anything interesting
I am really confused, I don't know what to do
I just plugged this function and the original function into desmos, they aren't equal?
also, the rational root test might be beneficial for you
as they stated
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I'm trying to understand something related to units when multiplying that I've always taken as given but never much given it thought:
Say like we have here: 30 degrees * pi radians / 180 degrees = 30pi/180 radians.
I understand the math behind how this works but I can quite understand why the degrees cancel out?
The degrees cancel eachother out. why? I get why the number math here works but the units of measurements cancel out why?
<@&286206848099549185>
🙏
Seriously sorry for the ping.
imagine you have a number x, and then you multiply that number by its multiplicative inverse, i.e 1/x. the x's cancel out
its sort of the same concept
but with units
∘ / ∘ = 1
x/1 * 1/x = x/x = 1 but like, in the example with degrees, because degrees / degrees = 1 then 1* radian is radian?
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Appreciate the help.
np
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I just had to go do something, I know the rational root theorem and I know how to use it but I am looking to understand and use other forms of factorization
@visual hazel Has your question been resolved?
they're not practical for this question
I am still wondering why the book says the other function was equivalent though
This
you could attempt to introduce expressions to complete squares / form groups, but it's not easy to spot what will be helpful here
based on what was written book is incorrect
,W expand (x-1)(x+1)(x^2 +5)
ah...ic
that's different from the expression presented to us
and is more reasonable to factor without having to apply rational root theorem / long division
@visual hazel
did you make a typo
that's right, the book has a typing error
I am going to try now
a⁴ - 1 + 4a² - 4
(a⁴ - 1) + (4a² - 4)
(a² + 1)(a² - 1) + 4(a² - 1)
(a² - 1)(a² + 1 + 4)
(a - 1)(a + 1)(a² + 5)
now yes :)))))
thanks
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need help
i have no idea what to do, apparently 0.18 is wrong
tried the slope formula
,rotate
that should be close to the answer
but still help
if you're in the right mode
still probably missing parentheses
yes
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How do I simplify $\tan^2x-\sec^2x$
Matt
I know that tan=sin/cos and sec = 1/cos
pythagorean identities
so it should look like $(\frac{\sin(\theta)}{\cos(\theta)})^2-(\frac{1}{\cos(\theta)})^2$
Matt
but idk how to simplify from there
distribute the squares through the parentheses
ok so then itll look like $(\frac{\sin(\theta)^2}{\cos(\theta)^2})-(\frac{1^2}{\cos(\theta)^2})$
Matt
,tex First, we know that $\tan^2 x = \sec^2 x - 1$ from the Pythagorean identity for tangent.
Lia 👅
$\frac{\sin(\theta)^2-1}{cos(\theta)^2}$
Matt
how do i use the pythagorean identities for this
i know this identity but
how did you end up with this
i moved sin^2(x) to the other side?
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can anyone help me finish this up
is the first system inconsistent or consistent
im not sure
you said they were dependent
what does it mean for them to be dependent?
isnt it with the same slope & y interc
@haughty prairie Has your question been resolved?
@haughty prairie Has your question been resolved?
anyone??
I think you still need to classify the top and bottom as consistent or not
yea i solved it already but now im wondering if this is right
options 1 and 3 don't even make sense
option 2 is correct, can you explain why?
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Let's say we have an exponential function, $y^x$. At the point (0,1), we have a tangent with the gradient 1. How would we calculate the value of y?
sin city ☆
youre not using the most intuitive letters here
can we switch it?
$f(x)=y=a^x$
jan Niku
so whats $f'(x)$
jan Niku
sin city ☆
,w derivative a^x
👀
okay
we know here that the value of x would be zero
yes
so we substitute that in
and its equAL To what?
it’s log a
well they say it has a gradient of 1 right
yes
specifically the information tells you that $f'(0)=1$
jan Niku
,w a^(0)log(a)
oop
hold on
whats our formula for f'(x)?
what? no
$f(x)=a^x$
jan Niku
what is $f'(x)$
jan Niku
$a^xlog(a)$
sin city ☆
thats the derivative, right
okay, $f'(x) = a^x \log (a)$
jan Niku
yes
and we know $f'(0)=1$
jan Niku
sin city ☆
correct?
mhm
which becomes
simplify
is the slope 1?
$log(a)=1$
sin city ☆
a= e
this log is ln tho
the euler function
yea
I GOT THE PROOF
yes
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Can someboady explain to me how to calculate angles in non right traingles?
depending on what info you have
sine rule and cos rule would be useful
Uh okay
example
to my best understanding
c is 7
b is 5
a is 3
what is C angle
the diagram looks like c is x and a is y and b is r
Cosine law would get you this
doesnt cosine law only apply to the first part
