#help-17
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what is u
^
Just the substitution method of integration
$-\frac{1}{3}\int \left(4-3\left(4-3\right)\right)^{-3}$
svnset
is this what you mean
Wtf
wait let me think
Who are you pinging for? The guy with the question?
You successfully found dx in terms of du
From this, you have u = 4-3x, you have that exact thing in your integral, so substitute it out
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I have to prove this claim, however I am not quite sure where to start and how to progress, I know I have to do a direct proof by cases, which would be when x and y are the same sign or different sign.
I did something similar to this which was the triangle inequality I think, but I did that in class, and not sure how to do this.
hmm
well yea with the triangle inequality we have : |x+y| <= |x| + |y|
now the main problem is how to get max(|x|, |y|)
Yeah, i just don't how how to start or do anything, I started proofs not too long ago so its still mega confusing
can we say that |x| <= max(|x|, |y|)
I mean its kinda true because max(|x|,|y|) is either |x| or |y|
its true for |y| too
therefore |x| + |y| <= 2 max(|x|, |y|)
well yeah
in conclusion, |x+y| <= 2 max(|x|, |y|)
i dont get how this helps
?
i mean this is the claim
ok
so to start the proof itself, i said that x and y are of either the same or different signs
at least thats both of my cases
oh you are saying that either |x| or |y| is going to be returned from the max function?
so |x| = max{|x|,|y|} and same for |y| too?
$\operatorname{max}(|x|,|y|) = \begin{cases} |x| & |y| < |x| \ |y| & |y| > |x| \end{cases}$
Herels
oh i see
since |x+y| <= |x| + |y|
and |x| + |y| <= 2 max(|x|,|y|)
we have :
|x+y| <= 2 max(|x|, |y|)
oh i see ok that makes sense
i have to follow a certain set of reasonings though let me send it
algebraic reasons
yea because a <= max{a,b} same for b
i have to do this in cases though so how would i do that
Sorry I don't know how to use your tables
here is how I would write it :
For $x,y \in \mathbb{R}$, we have, by the triangle inequality :
$$|x+y| \leq |x| + |y|$$.
We know that $|x| \leq \operatorname{max}(|x|,|y|)$ and $|y| \leq \operatorname{max}(|x|,|y|)$ with $$\operatorname{max}(|x|,|y|) = \begin{cases} |x| & |x| > |y| \ |y| & |y| > |x| \end{cases}$$.
Therefore : $$|x+y| \leq |x| + |y| \leq 2 \operatorname{max}(|x|,|y|)$$
In conclusion : $$|x+y| \leq 2 \operatorname{max}(|x|,|y|)$$
Herels
yeah its just i was never taught that idk
if you werent, you can just prove it
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In the household of family Huisman on a winter day a window with the surface of 3m² lets go 1,2MJ (1,200,000 Mega Joule) Of heat.
Make the formula for heat loss, Q in MJ and window surface in A m².
TRIED MY BEST TO TRANSLATE IT. Please help.
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how do you know if a linear system has infinitely many solutions vs just one
Calculate them
You can also check the relations of the coeficients
very helpful
Does your system have a free variable?
Thanks, it heavily depends on the system of equations.
That's one way to put it
fair enough
The key here, though, is that x3 is a free variable
you can have x1 and x2 be equations but x3 isn't
In which case, x1 and x2 will be fixed anyway
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Hi
!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
2
So the initial velocity is 5.5 meters per second
How much should the runner accelerate at rate of 0.2 for the runner to complete 1100meters in exactly 3 minutes
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I've posted the answer and question. But I'm not really sure about the details of the answer
why can't a point right of q2 be zero?
why does it have to be left of point q1?
is it because |q2| > |q1|?
yeah thats what it says
dam i silly
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i thought absolute takes negatives away
-2 + 2 = 0
wdym
|-2 + 2| = 0
how
youre mistaken about how absolute values work
youre thinking of it as: |-2| + |2| = 4
your graph is y = |x + 2|. what is y when x = -2? 0.
we see that on your graph
y(-2) = |-2 + 2| = 0
(-2, 0)
im supposed to graph it
x = -2 here
what plus 2 equals 0
-2
boom
so x is -2
ur confusing the equation for |x| + |-2|
basically forget about the absolute value signs and complete the equation
because if you think x can be positive it will be |2+2|
which is 4
yes
you should understand the logic behind it and not just memorize that idea
yeayea so what makes it equal zero
yes
yesokok
i get it now
tyty
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So I have this function
I'm told to find f'(x) and show that it is positive for this interval
well
I get that f'(x) isn't defined in 3
meaning either I'm failing to understand something or the exercise is wrong and should've been ]3,infinity[ instead
am I missing something?
@glass jewel Has your question been resolved?
@glass jewel Has your question been resolved?
You did the exercise with a computer program?
The program doesn't know the derivative at x = 3 because you told it the function is undefined at x < 3.
f(x) is defined at x = 3, but derivatives are defined as a limit. Your program is unsure whether the limit exists at x = 3.
When is $f(x)$ defined? Is it only defined when $x \geq 3$?
chencking
Why? Why can't you calculate f(2), for example?
I can, but the exercise says it should only be defined when x>=3
I mean, it defines f(x) like this
Oh wait nevermind I missed the part of the question restricting the domain.
So one way to approach the problem is to just extend the domain of f(x) and using that plug it into your program.
The other way is to just calculate f(3) yourself and then use the program's derivative for the rest of the interval.
I guess
it's just kind of weird as they specifically require us to use this program and it seemingly has troubles with their own exercises
Simply put though, your program could not find the derivative at x=3 due to the way they programmed it.
Referencing the screenshot in the comment I replied to, we know the limit is simply the limit when h approaches 0 from the positive direction. However, the program does not, so it made it undefined.
I am not confident, but my guess is that rather than restricting the domain to $[3, \infty)$, it seems the way you entered the function simply left it undefined on $(-\infty, 3)$.
If this is for a college course, you could try asking your professor or TA if there was a better way to enter it. Or perhaps a specific way they wanted you to use this output.
chencking
Yeah, I'll probably ask someone tomorrow, but thanks for the help, it was really useful :)
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Is this correct?
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i ran this thru a calculator and it still says there are no removable discontinuities, i put DNE there and it said i was wrong
is it not -3?
why would it be -3
the denominator factors into (t+3)(t+5) so there is a discontinuity at t=-3 but its removable since t+3 cancels with the numerator
ahh thanks
i forgot about that because i had already factored it and simplified to 1/t+5
one more question
what do i do here
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4a
Uhh
did you write a formula for each f(-x) and g(-x)
And compare it to f(x) and g(x)
no
but odd is if it has rotational symmtery
along origin
and the rational
x cannot equal 0
so
how is it odd
yes
What does it mean
it has rotational symmetry along the origin
No
yes
So do this
And
Do they satisfy this
Yes
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!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
@coarse ridge Has your question been resolved?
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for problem 6, would the formula for the homothetic transformations also involve the step mentioned in the example from problem 5? like for 6a, would i need to shift the plane to be centered at i, then do the stretching, then shift back?
or would it just be a shift there and then stretch with no moving back?
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i was asking ab this one yesterday im still completely lost ive been watching some videos and i think i have to rewrite the square root to get it to match the formula for arcsec however im not sure how to get there
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<@&286206848099549185>
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The answer is supposed to be 120pisqrt26 but I can't seem to get it
@slate island Has your question been resolved?
Where even is the question
find the surface area of the volume generated when the following curves revolve around the y-axis.
If you cannot evaluate the integral exactly, use your calculator to approximate it.
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<@&286206848099549185>
posted the question
also its 197
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I am not sure how to go about this porblem
problem*
Could someone guide me in the right path please
write an expression for F’(x)
F(x), and yes
and now you can evaluate F’(5)
Im not sure how to fully do that, this topic is still new to me. Would I plug in 5 to each of g(x) and f(x) ?
the question asks for F’(5), i assume you were taught derivatives
note F’(5) isn’t F(5) which is what you were suggesting
right. Were still learning it. My professor has a really heavy accent so I am falling a bit behind. To be honest I am completly lost on what to do after to evaulate F'(5)
okay, can you write an expression for F(x) without f(x) and g(x)
so not F(x)=f(x)+g(x)
where’s k coming from?
would it not be the constant
of both functions
or am I completly speaking giberash and thinking of something else
the constants are contained in f(x) and g(x) already
ahh okay
so all you need to do is substitute f(x) and g(x) with the expressions you got above
okay so we would have F(x) = [1/2x + 2 + -2x +10]
yes, and you can simplify that a bit
yes, now F’(x) refers to the derivative of F(x), or how the value of F(x) changes as you change x.
( i would start recommending reading up derivatives of a straight line somewhere online )
yes then find F’(5)
okay let me see real quick
ill post the derivative of F(x) if you can double check for me
wouldnt the derivative of our function F(x) just be - 1/2
got is so if we have the derivative of F'(x) = -1/2 how would I evaluate F'(5) <-- ( If this statement is right )
oh
but repeat the steps you just took will lead you to the right answer
: (
okay
just to confirm is this right F(x) = [1/2x + 2 + -2x +10]
i got -3/2x + 12
rooki mistake
yes now it’s fine
you already have F’(x), so what do you do when you want to find F’(5)
it should be the same thing you do for any function when hon want to find it’s value at some point
oh so wouldnt F'(5) just be equal to -3/2
yes
I see
Thank you so much for your help and time
I have one more practice I can do and repeat my steps
Thank you ❤️
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Hi! First time ever doing stats, can someone PLEASE check over what I did, thanks
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x = 0 and x= 1 are parallels
solve x=sin(4x) for 0<=x<=1
,w graph sin(4x) = x
Do you mean intersection points of y=x and y=sin(4x)?
I haven't seen term intercept being used for intersection points.
Anyway, you can't solve conventionally, i think. Graphing tools seem like your only help or root estimation techniques.
or intermediate value theorem
Of course, there is.
You just can't find it using your general isolation or such root finding methods.
,w solve x=sin(4x)
There you go.
What makes you think that number is in some surd form? Not every irrational number is in surd form.
On the top of that, we don't even know if x is irrational. Lol
intermediate value theorem is more of an existence theorem
Yeah. That won't give you an exact value either.
If you made a small enough boundary tho
Idk prob doesn’t help
Sorry
hmm
I mean, its possible to find a value but I forgot how
It’s p useless tho
Cuz you would have to know the value
Also oops I hijacked
no but if you know the boundary of the x such that f(x) - x = 0
you can try dichotomy or smthing like that
That’s true
Since calc?
maybe
No basically in a continuous function f across a domain (a,b)
$\forall y f(a) < y < f(b) \exists x$ s.t $f(x) = y$
NoSQLDB
Wait why is the latex spacing so shit
well, you can do spaces but i dont know how
you normally put quantifiers together at the beginning
,,\forall y\in(f(a), f(b)):\exists x: f(x)= y
Doesn’t matter tho
Okay that’s wayyy too much
🤨
It’s okay I love the effort
if I haven't found a counter
its worth attempting to prove it
uh yh lol
this is what ur tryna prove
Yes thats how they differ
but it may turn out not to matter
im not what to say except youre going to need to expand the definition of max
in a symbolic proof
if im not mistaken it might not actually hold
but trying to prove it will hint you towards constructing a counter example
Doesnt matter - just try out the steps you would to prove it
Approach for a proof should be fairly systematic.
State what ur tryna prove
k(f + g) = kf + kg for any k, f, g
Then start with one side
k(f+g) =
and start expanding/manipulating
???
Let k, f, g.
k(f + g) = ???
No, you need to prove this algebraically
the first step is to expand on definitions
yes geometry will give u the intuition needed
but this all needs to be symbolically manipulated
its all given to u in the question
k(f + g) only means one thing algebraically
it means
add f and g together
then
multiply by k
So first add f and g together - whats the definition of this
Let k, f, g.
k(f + g) = k max(f, g)
thats all i was looking for
you must expand definitions
Let k, f, g.
k(f + g) = k max(f, g)
= ...
So next you need to expand the definition of max
well you tell me what max means graphically
max f g
its a pointwise max right?
so ok we shall rewrite the proof pointwise
Let k, f, g, x.
k(f(x) + g(x)) = k max(f(x), g(x))
= ...
yes?
Then you can use the definition of max for real numbers
technically not but lets leave that aside
to expand the definition of max, hint: consider cases
Let k be scalar; f, g functions; x in domain.
k(f(x) + g(x)) = k max(f(x), g(x))
= ...
No.
what is max(a, b) in general
you need a definition for this otherwise ur stuck
and one way to do it is piecewise
yes
Let k be scalar; f, g functions; x in domain.
k(f(x) + g(x)) = k max(f(x), g(x))
= kf(x) if f(x) > g(x) else kg(x)
u can write that neater in braces
well yes? piecewise functions
so what im gonna say is that looks ugly and to split it into 2 cases
Let k be scalar; f, g functions; x in domain. Suppose f(x) > g(x).
k(f(x) + g(x)) = k max(f(x), g(x))
= kf(x)
= ...
ok now we're kinda stuck here, and what would be helpful in rough is to think about what we want to show
we want this
= ...
= max(kf(x), kg(x))
= kf(x) + kg(x)
yes?
so then u have to think for yourself when they are equal. And more importantly if they are always equal
well yeah, its just notation for the same thing
,,\max\cdots=\begin{cases}case A\case B\end{cases}
I think u have all the pieces to finish the proof and either conclude distributivity holds or it doesnt with the above ^
so will leave it to you
it probably will read better on paper
If it doesnt, u need to come up with an explicit counterexample
but the point of writing everything above is to help u come up with it
(supposing there is a counter)
i probably wont be around
but someone should be if u just type
yh i did above, promise. reread all of it carefully
before i disappear f+g is defined pointwise.
but "f+g" itself is a legitimate new function. That is defined in that way
with regards to the earlier notation
technically i miswrote when i wrote
f+g = max(f, g)
its an abuse of notation
max is takes 2 real numbers as input
unless i define a new max which takes 2 functions as input
which does exactly what that oplus operation does
ie. max pointwise
so when ur tryna prove
kf+kg = k(f+g) this is functional equality
2 functions are equal iff they are equal everywhere pointwise
note even kf is a function. Defined pointwise by (kf)(x) = k(f(x))
obvsly on paper stick to oplus, not +. super confusing in text 
error on...
5th equals does not follow
thats all fine
u have good ideas
but unfortunately this does not hold in general
nope.
dont wanna give it away
but yeah think on this carefully
in particular note a proper proof states what k, x, f, g are. As in what kind of objects they are
and that's important
Whats k.
eh???
f, g are functions (of the type stated in the original question)
x is in the domain
k is ...
like what set
yes, now rethink this claim
well come up with some examples of them
and check a > b => ka > kb works or not
there are plenty which dont.
Right, but now u see this point. Its a key point with regards to the original question
well state me some k, a, b where it doesnt work
to be sure we re on the same page
well yh
just to be clear this claim doesnt generally hold
no.
ok shelving this aside (since i do have to disappear)
once uve found k, a, b. Great.
Now go back to your original proof
think about if it can be rescued
If it cant, that means uve probably come up with a counterexample
and then u should state it explicitly (let f = ..., etc)
oh yh and nitpick: one of your cases need to include the case f(x) = g(x).
for all the casing ur doing
well there u go lol
at the very least
k can be any real right
right ok i see your point
there is another k
half the k's dont work
show me what u get with negative k...
eh.
thats the point of expanding the proof
though
to break it into chunks
in this case yeah u wouldve missed it
but for someone marking or helping it helps pinpoint the issue
like this
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what didnt work
ur gonna have to pick a specific x as well

-1 . max(2, 4) =/= max(-1 . 2, -1 . 4)
thats correct. theres only one faulty line in your proof
now its a question if it can be fixed. or if what ur tryna show is false.
this is like correct, no problems
but u wanted to have it inside for... reasons.
huh
no?
no no no
ur either doing a proof to show theyre always equal
or ur stating a counterexample
to show theyre not
Theyre equal for all choices of k, f, g, x
is what u wanted to show
the negation of this statement is that there are some k, f, g, x where they not equal
yes but no. you need to give specific k, f, g, x
maybe but why not just come up with something concrete
to show 2x not equal to x^2
u should like
x = 1 disproves it
cus it does hold for some x maybe. like 0 and 2
well no, it defo works with positive k
u havent exactly shown it doesnt work for negative k
not with your working
its much much easier for a proof verifier
to check 1 specific case
rather than reading your proof of a certain class of cases breaking it
we only need 1
yes thatll do
x = something too
it distributes for x = 1
and x = 0
yes
k(a+b) = ka + kb
thats all it means
-1 max(f(0), g(0) = max(-1 f(0), -1 g(0)) is indeed true
np, this is a common thing to struggle on
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substract 9^3x * y from both sides, take 9^3x common, and then solve for x and y
hmm actually nvm
just divide both sides by 9^3x
y eah and y=81
Yeah so as I was saying since you know y is 81, then you effectively have 9^x = 9^x which means X can be anything
In the other channel
X could be smaller, could be bigger
righht i was away sorry
so replied late
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Can anyone give me a quick real life example of a biased and an unbiased estimator?
Suppose you randomly sample only the tallest students from a school to estimate the average height of all the students. This would be a biased estimator
And unbiased would be randomly sampling in such a way that then mean of their height is very close to the actual mean?
yes
So the estimator basically depends on our sampling?
yes the performance of an estimator can depend on how you're sampling the population
Hmm okay
But the estimator itself would be a function that for example calculates the mean of our sample
And its value is our estimate
Is that correct?
Ty anyway, the example helps
.close
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How to do this x²-11x+30=0
Quadratic equation
Can I have explanation
@midnight marsh do you know how to solve quadratic equations generally?
U there?
@paper depot
sorry had to go do urgent shit irl
yeah checks out
that doesnt matter i think
but you could do the x1 when it is a plus
or x1 the result of the biggest number
is the same i guess
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hey i was wondering how i would find the derivative for this.
i was thinking i could bring the denomenator to the top
to get rid of the fract but honestly i dont really know how thats
use the 'quotient rule'
suppose to look like
use the 'chain rule'
wait..... i thought quotient rules only for an x variable divided by an x variable?
yeah this works too
if i were using chain rule
would i just find the derivative of 1/x
then multiply
it by the derivative of 5x^2+6x?
I uh think you should use quotient rule
that would be a different answer
(-10x-6)/(5x^2+6x)^2
substitute 2 in
huh
@hushed nexus Has your question been resolved?
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The working is correct
I hope you meant this expression
$ax^{a-1}sin\left(\frac{1}{x^b}\right) + x^acos\left(\frac{1}{x^b}\right)\left(-\frac{b}{x^{b+1}}\right)$
And not $ax^xsin\left(\frac{1}{x^b}\right) + x^acos\left(\frac{1}{x^b}\right) -\frac{b}{x^{b+1}}$
- Miles12345
x^x?
I believe he meant $x^{a-1}$
chencking
Yes. Apologies for the typo
- Miles12345
Do you understand what it would mean for $f'(x)$ to not be continuous at 0?
chencking
I don't understand
Please explain
Assuming $b > 0$, $\frac{1}{x^b}$ blows up as $x$ approaches 0. So the limits of $\sin(\frac{1}{x^b})$ and $\cos(\frac{1}{x^b})$ are undefined. However, $\sin$ and $\cos$ are bounded, so the limits of $f\sin(\frac{1}{x^b})$ and $g\cos(\frac{1}{x^b})$ exist when the limits of $f$ and $g$ go to 0 as $x$ approaches $0$.
Can you see how that is similar to your problem's $f'(x)$? What would your $f$ and $g$ be? Under what conditions does their limit approach 0 as $x$ approaches 0?
Yes
So you need to figure out under which values the limits of your $f$ and $g$ will be 0. That way, the limit of $f'(x)$ at 0 will exist.
chencking
Yes
lim x tends to 0
Xsin(1/x)
So this function is continuous at any point right?
Not at any point unless you specially define F(0) = 0 (where F(x) = xsin(1/x)) in a piecewise fashion
Since 1/0 is undefined
Not at all
1/0 is undefined
So 0sin(1/0) is still undefined
But if you specifically define f(x) as xsin(1/x) for x≠0 and f(x) = 0 for x=0, then f(x) is indeed continuous over R
@elfin moon for continuity, you need to check the Right Hand Limit (as x->a^+) = Left Hand Limit (as x->a^-) = f(a). This boils down to saying that there should be the existence of the limit of f(x) as x->a and should be equal to f(a).
Now in the question, it is specifically said that for x≠0, f(x) is defined as that expression, and for x=0, f(x) = 0 (since plugging in x=0 in f(x) which is defined for x≠0 gives an undefined value).
When you check the existence of the limit of f(x) as x->0, upon restrictions on values of a and b, you get the continuity at x=0.
So you need to find those restrictions
@elfin moon Has your question been resolved?
I didn't understand your last restriction lines
Why specially x>0
Apologies for the confusion. I meant -> symbol as the arrow symbol used in limits
@obtuse sierra please help in this question
I am confused because one user said b>0 and f,g should be zero
I am confused what should be zero and what should be postive
oh hey
i dont want to read this entire discussion (lazy), also is the answer D?
@elfin moon
ping me when you're back
ok
Limit, DIFFERENTIATION, continuity sab mix ho gya🤦
we have this
Yes
now we want this to go to 0 when x = 0
Acha
whatever is the argument of sin and cos, they always stay between -1 and 1
wait a sec, brb
Yes
so you need to focus on the x that is in multiplication with those two
those two should make f'(0) = 0
that means there must be a term of x in the multiplication
but not in denominator
otherwise infinity
understand what I just said?
second?
I meant when power of x (b+1-a)>0 then it will be 0
But first wale ka malum ni
a - 1 > 0
a=0?
that term should also go to zero when x = 0
From here
ohh?
you only have sin(1/x^b)
put x = 0, do you get x = 0?
,w plot sin(1/x) from - 1 to 1
Infinity
Yes like that oscillation
Like what?
so what will you do?
Any medicine for it 💊
we have -a+b+1 >0
a-1>b
By second thing
do you understand that we need x multiplied with sin(1/x^b)?
It should be 0
What limit? 0?
agar sin ke saath x nai hua toh oscillating limit ho jayegi
a=1, x=1
agar x ki jagah 1/x ya 1/x^2 ya 1/x^3 hua toh infinity bhaag jaayegi
agar x hua ya x^2 x^3 x^4... toh 0 jaayegi.
Bahar wale x ki bat kar rhe na abhi?
yes
nope
,w draw 1/x sin (1/x)

,w draw x^5 sin(1/x)

1/x me x increasing karenge toh ye sin(1/x) ko jyada motive karega so infinity
And x× hoga jab usko niche layega which is 0
Yooooo

Ha x=0 se Jayda samaj aaya😂
Let's go back to point
So we want x to be positive so that it makes whole 0
a-1 should be greater than 0
Yooo both term connected now
a-1>b>0 yooo damn

exist nai continuous
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Is their a different method to factor x^3+4x^2-15x-18. I want to use something thats different than the rational root theorm.
there is the cubic formula but it's painful to use
rational root theorem is by far the best option
ok
I can tell you
sure
Try putting 1,-1,2,-2
If one of them satisfied then x-a will be one root then simply divide it and solve quadratic
ok
that is basically the rational root theorem
except your doing polynomial divison after finding out one number that satisfy's it but yeah technically same thing
Yes
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well the point is that the rational root theorem tells you which numbers to test
instead of always blindly testing 1,-1,2,-2,...
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hi
I need to find out whether this function is injcetive
I know that injective means that each element in the domain maps to only 1 in the codomain
But I don't know if I should approach this by doing a 'counter-argument' where I need to prove that it's not injective or what
it goes from R -> R
@copper pebble Has your question been resolved?
Try to find the roots of your polynomial
Find the roots of your polynomial and see if it means that it’s injective or not
Okay, thanks
after finding roots, how can i determine if its injective or not
Like you said, a function is said injective if for all $a, a’\in A$ such that $f(a)=f(a’)$ we have $a=a’$
Joseph.P
Are you still here ?
What did you find as a root ?
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I am attempting no.2
and I have no idea how to do it
what does a(underscore) b(underscore) even mean
any help
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I am stuck here
I think I need to use the lb and sin/cos + the angle
I just dk what combo is used for what
like is P1x 190sin(40)?
or is it 190cos(40)
or am I completely off base
sin = opp/hyp
And the hypotenuse is always the actual length P1
Know how to draw the triangle, such that P1 is the hypotenuse? One side will be the x-axis, another side will drop down
Make sure you can do it the "correct" way by drawing a triangle and finding the length of its sides
for P3 I can use the fact its a 30 60 90 triangle right?
Could I draw a right triangle from it
But I do have a bit of a hack. If you instead find the angle going ccw from the positive x-axis, then cos is always the x-component, and sin is always the y-component
So for example, you can get to P3 by going -30 degrees from the x-axis.
x-component is 120cos(-30)
y-component is 120sin(-30)
-30?
Should be pretty normal if you've been working with the unit circle
That's probably not the way you've been taught, but imo it's a cheaty way that allows you to ignore drawing triangles
wait do you have to take the absolute values of the answers?
bc 120sin(-30) is -60
can you have a negative force component?
Sign is needed. That means "downward".
oh true
Or "leftward" if you're working with the x-component
You are disagreeing with your own answer
Oh nvm mb
oh I think ik why my last are wrong
So I was talking about P3 above, not P1. What angle, starting with the positive x-axis, do you need to get to P1?
ohhhhh
I am dumb
one sec
I am all mixed up
for that I used 190cos(-140) and 190sin(-140)
where did I mess up?
,calc 190cos(-140 degrees)
Result:
-145.54844419261
Hmm. I like your answer. That's odd.
?
theres a space between the number and the negative
neither of the other ones that are marked right have that
Oh yeah, your negative does look very different. Type something wrong?


