math-help

[balmy drift]

its verry usefull

[left knoll]

Yea I have it,it’s what I used to send the sum lol

Now that I looked at the sum more,it makes more sense and I understand It lol
Thanks guys ☺️

[balmy drift]

Np gg wp

[timber galleon]

https://tenor.com/view/bianca-rinaldi-atriz-xau-ribeirao-do-gif-13217595

[nocturne island]

does anyone here know matlab by any chance?

[analog wagon]

Help me in questione 1 n 3 section F.. I'm getting 4 in q 1 but the given ans is 3 n for q 3 what's the significance of 1/2+ n 1/2

[supple island]

1/2+ and 1/2- mean that you're respectively approaching 1/2 from the left and from the right

[supple island]

also the answer in 1. can't possibly be a=3, it's actually 6, here is also visual proof

[steady nova]

help pleasee

[edgy crag]

Can anyone show me how to do letter d please? I know the answer i just dont know how to get it

Ohhh nevermind i just got itt

[covert anchor]

guys how do i show

[inner tartan]

Find the discrimanent

[analog wagon]

I tried to solve it somewhat like this(actually it's gonna be hard for me to plot these graphs in the school)

N the graph

[analog wagon]

So can I directly put x=1/2 in that equation? Thnx!!

[static steppe]

help me solve !!!

[supple island]

uh yes and no, just mind that 1/2+ is a little more than 1/2 and 1/2- is a little less, so for example lim x->1/2+ (12x^2-3)=0+

[supple island]

ok so here i thought that (a-3) was all multiplied to the limit so my bad, the answer i get is a=pi

[full venture]

Someone halp meeee

Q11

Is there no other way other than !!!!!!!

[analog wagon]

Thanks a lot!!

[analog wagon]

Okkie

[full venture]

yo anyone can halp me ^

[edgy crag]

Can anyone explain how to get the answers please im trying to study rq for my finals

[north schooner]

hey!
a. Concept used: point-slope form of a line
formula: (y-y1)=m(x-x1)
in this question x1=1 y1=4 and m=5
now,
y-(-4)=5(x-1)
y+4=5x-5
y=5x-9

b. Concept used: slope-intercept form of a line
formula: y=mx+c
in this question, given: 5x+3y=18
now we try to change the given equation in a form which looks like the formula
so we transpose:
3y=-5x+18
now we divide by 3 on both sides
y= -5/3 x + 6

c. Concept used: two point form of a line
formula: (y-y1)= [(y2-y1)/(x2-x1)] (x-x1) where (x1,y1) and (x2,y2) are the coordinates of the points through which the line passes

in this question: x1=1 y1= -4 x2= 0 y2 = -2
now
y-(-4) = [(-2-(-4))/(0-1)] (x-1)
y+4 = -2(x-1)
y= -2x -2

d. Concepts used: -the slope of parallel lines are equal
-point-slope form of line
slope of line y=8x-2 is 8 [found out on comparing with y=mx+c where m is the slope]
now, x1= -1 and y1= -4
(y-y1)=m(x-x1)
[y- (-4)] = 8 [x- (-1)]
y+4 = 8(x+1)
y=8x+4

I hope you understood the questions. If you have any doubt feel free to ask. I would also recommend you to revise the theory again using a book or video lectures and solve a few illustrations.

[covert anchor]

how do i use this

[edgy crag]

AHHHH OMG THANK YOU SOO MUCH <333

[north schooner]

haha welcome my friend if you have any other doubt you can ask

[edgy crag]

yeahhh i will thank you again :)

[north schooner]

have a good day

[edgy crag]

you too!!

[acoustic delta]

may be like this?

sorry but I didnt get exactly your question

[covert anchor]

like

say you got

(x-1.3)(x+5)>0

how do you express it properly

[edgy crag]

Can anyone explain how to get b?

[pine kelp]

@mental snow You can't do that. That's wrong.

[acoustic delta]

All natural numbers from 1 to 10000 were written out on the Board in ascending order, and then they erased those that are not divisible by either 4 or 15. What number was in 2017?

[left knoll]

Can someone who knows math or physics or chem help me with some basics?
I suck at math and physics but I wanna get better at them.

[modest compass]

The vertex will be (-9,-16), to find if it's a maximum or minimum (assuming you have to prove it) expand and differentiate twice and plug in (-9) as x. If it's greater than 0 it's a minimum and if less it's a maximum

[thick pine]

You can already see from the sign that it has to be a minimum, sgn(3(x+9)^2) = +1. No need to diff.

But yeah if you have to prove it you can differentiate

[edgy crag]

Does anyone know the answer? i really need some help pleasee

[modest compass]

what does sgn mean?

[thick pine]

signum haha

[modest compass]

I've never seen that before lol

[tardy bone]

I am so endlessly confused by my worksheet I'm actually considering that it has a printing error. so we have this table of combinations of 2 random variables and we have to fill out the probability of the combinations or of an individual varbiable taking on a specific value. this is what it looks like

[thick pine]

https://en.wikipedia.org/wiki/Sign_function

[tardy bone]

with this being their solution

and howwww tf does it make sense to have 1/6 in line 2 column 3

thats impossible right?

1/2 * 1/2 is NOT 1/6

right???

this is their explanation but it doesnt mention the field

so yeah thats a print error right?

[tardy bone]

pretty sure exponential

[thick pine]

No it's quadratic. But I didn't answer because I won't help to cheat on live tests

[queen rover]

Also, it's against the rules

[marble terrace]

So in 3 days i have a mini-exam since I got 9 points out of a max 20 points in my final exam. Whats the best way to do a revision of all the lectures? I'm taking calculus

[queen rover]

if you have to reproduce proofs you have to study those too, if not you could skim through the lectures and and gather the most important formulas / theorems, learn those by heart and then make exercises

[tardy bone]

Nvm

[marble terrace]

i have limits, successions, series, integral and derivatives

[queen rover]

yes but you probably have an idea if the educator will ask for proof of the theories, besides exercises

[sharp ferry]

Isn't she talking about the 3rd one ?

[sharp ferry]

The 3rd part of the 3rd question 3x²+9x-4 is a quadratic function

[tardy bone]

oh yeah sorry confused the 2 for a 3

[left knoll]

Hey guys can someone help me?

[sharp ferry]

You can use the fact that the sum of all angles in a triangle is 180°

[left knoll]

40

[sharp ferry]

One angle is 90 other is 40+X and the 3rd one is 50° so

Just equate it 180

[left knoll]

I know that

[sharp ferry]

Yea then?

[left knoll]

There are two unknown angles

[sharp ferry]

Isn't bd a straight line?

[left knoll]

B point is not 90°

[sharp ferry]

Yea can't exist then?

[left knoll]

Yeah

[sharp ferry]

Oh that square thing

Got me confused

[left knoll]

Sorry I forget to erase that

We don't know angle B

AE and BC bow is equal? So I think like that

[sharp ferry]

You can use the fact that in a cyclic quadrilateral if the opposite sides are equal then the other 2 sides are parallel then?

Ab is parallel to CE

[left knoll]

CE is not straight line

Oh I see

[sharp ferry]

Yea well I was just suggesting something I'm thinking about it

Wait let me grab a paper otherwise I'll do some error if I do everything in my head lol

[left knoll]

Okay hahaha

[sharp ferry]

I think it's 50 degrees

[left knoll]

Answer is 25°

[sharp ferry]

Uhhhh

Lemme see if I did some error

Ohhh yeaaa

I forgot to divide by 2

I got 2x=50

[left knoll]

How many degrees is the C angle?

Okay okay I'll try to understand

Okay thx a lot

Good night 😪<33

[sharp ferry]

bruh

Lol wait imma send the complete working

@left knoll imma sleep as well now lol

[left knoll]

Ahahahah thank u bro

[sharp ferry]

Welcome

Can someone help me with this :/

[left knoll]

I don't know how to do more

[slow elbow]

@left knoll hey bro i tried the problem you sent earlier i got different answer from others though

[left knoll]

Can you send me your answer?

[left knoll]

i think the ans is c

[left knoll]

Its pretty much done, then you just have to use the range for sinx which is -1 to 1

[left knoll]

I don't know, but it seems wrong

[left knoll]

U re right, I suddenly forgot that

[left knoll]

But thanks a lot <333

Can you help me again, again and again?

[oak sphinx]

Does anyone know how to solve this integral? Some of the programs I tried to use either cant solve it or dont offer a step by step solution/have an incoherent line of argumentation.

Needless to say my own attempts of trying to solve it failed.

[weak mortar]

well first thing you can do is split the domain of your integral and integrate one part from -oo to 0 are replace |x| by -x and then the same reasoning for the 0 to +oo part

[oak sphinx]

That works, thanks!

[jaunty belfry]

(My name is Vaughn and im not sure how to do this)

[mental snow]

You can use

Graph if |x| for V
For A you can invert by typing -|x|
For g you ll have to use different constraints in circle equation and some st lines
For U u can just use semi circle
For H just use straight lines
For N use parallel lines and then use a diagonal line

[brave ledge]

umm is this using u=2x^4+15 dx ??

but i didnt find it, the result end with 3/4x (u)^5 du, is this can be solved ?

[brave ledge]

it's ok tho

ty

[lost galleon]

hi

Hello..Can someone help me solve some questions about mathematics for my sister in the tenth grade

[left knoll]

send them here

[lost galleon]

8x^3 +12x-5/2x+3

[left knoll]

do u need me to explain or just send the solution? @lost galleon

[lost galleon]

solution

[left knoll]

gimme a moment

[lost galleon]

ok

g(x)=6x^3-7x+3.......f(x)+x^2-4x+1 find g(x) +x^2*f(x)

[left knoll]

This is how I do it—I don’t know if the same method is used by your sister’s school or no

[lost galleon]

Thank you..a friend helped me

[left knoll]

alright np

[lost galleon]

Thank you with all my heart for trying

[full venture]

Q11

Halp

[inland marten]

Hi ,can anyone help with question 4?

[supple island]

question 5 is not in the picture

[inland marten]

I meant 4 sorry

[ember kernel]

DM me if you don't know how I was able to split the equation on the 5th line into a linear system of 2 equations for 2 unknowns

[inland marten]

Yep i understand ,thank you so much

[ember kernel]

You're welcome !

[brave ledge]

uhh anyone? i still curious bout this

[valid elm]

Heyy I am stuck at part (b). How do you integrate it?

[modest compass]

I learned this today actually so it might not be correct but sinx integrates to -cosx and -sinx integrates to cosx

[left knoll]

I don't know how to divide with extra variables

[modest compass]

Expanding maybe might work so it'd be sinx - sin²x for f'(x)

[ember kernel]

To divide with parameters a and b, just consider them as usual scalars.

You can find them only using the "no remainder" condition, that's how you get the two equations 3-a=0 and b+12a-12=0

[left knoll]

Thank you so much! You're a lifesaver!

[ember kernel]

You're welcome !

[ember kernel]

I'm confused. Why is the gradient (of a two-component curve function) a scalar ?

[valid elm]

Alright, will try. Thanks!😃

[valid elm]

I'm pretty sure my math teacher did not consider that as she only set the questions to help us revise integrals. good eye though HAHA

[ember kernel]

Nah not good eye. I'm currently studying for an exam which consists in n-dimensional curve integrals. Here, the "curve" your teacher was talking about was merely the graph of f, which I didn't get

Tell me if my answer seems correct to you and matches what you've been taught about integrals and trigonometry 🙂

[ember kernel]

@brave ledge What's the question ? Because, at first sight and without knowing what you're asked to do, I would say this function cannot be integrated using substitution

[valid elm]

firstly, thanks for the guidance😃 i love the handwriting.

secondly, I haven't quite reached your level of mathematics so I'm afraid, I do not really understand it. Like I said, the question was given to us as revision only for integration, perhaps the teacher did not put in much consideration while setting it.

and yes, your answer was right, again thanks for the help

[ember kernel]

Oh, sorry I made it too hard. What are the lines or steps you didn't understand ? I'd be glad to explain them to you

[valid elm]

Nono, as in I do not understand what you meant by this so I do not know how to answer it.

but other than that the answer is all good

[ember kernel]

Oh ok ^^
Don't pay attention to my first message. At first I was just confused because your teacher used the words "gradient" and "curve", but their meanings are different in Calculus II (what I'm studying, college stuff). Only later did I understand what your teacher really meant.
(That's why the answer I gave you is adapted to your level and totally unrelated to my fancy multidimensional integrals ):smile:

[valid elm]

ahhh okay, that makes it much clearer. Thank you😃 👍

[covert anchor]

I'm iii where is c

[ember kernel]

Either it's a typo and it's supposed to be OAB, or you have to find the area of ABC, with C a parametrised point (Xc,Yc)

[covert anchor]

C a parametrised point (Xc,Yc

whats that

[ember kernel]

Forget that, I don't think you've learnt what it is yet

[brave ledge]

i dunno just that, and yeah same solution tysm

[ember kernel]

Either the coordinates of C are given in a previous question (if they're linked somehow), or it's a simple typo and they're asking you the area of OAB

[ember kernel]

Well ok, it doesn't make sense at all to me ^^

[hasty heath]

can someone help me with this exercise, I have to prove it with the induction principle

[lime nymph]

Well if it's wrong, delete it

[acoustic delta]

Gimme 15 min

[hasty heath]

thank you

[acoustic delta]

I’ve done @hasty heath

[hasty heath]

thank you so much

[acoustic delta]

No problems 😄

[eager crater]

hey is there anyone that could help me with my algebra 2 hw

[ember kernel]

Of course ! You can send a picture/screenshot here 😁

[eager crater]

awesome! this is the assignment im having trouble with

[ember kernel]

It's 2:25am here so I'll just go to sleep. I'll try to do it when I wake up

[glad sierra]

I'm guessing evaluate means sum of the series?

[eager crater]

ok thank you!

[glad sierra]

using Sn for arithmetic and geometric series to solve 1 and 2 (or so i understand)

[eager crater]

it doesnt have to be all of them help with even one problem would be really appreciated

[ember kernel]

That's what I've already got for 3 and 4. I didn't do 1 and 2 because they don't follow the same format I was taught for sequences. I don't want to give you possibly wrong answers

Sorry it's quite blurry

[glad sierra]

that was quick mate

i haven't done this level of math in ages haha but my guess for 4 was right

for 1 and 2, i have a similar doubt as to what they're asking
if it's the sum it's easy but is that what evaluate means? :/

[ember kernel]

Yeah me too, besides Riemann's series I haven't used sequences for 3 years

I think it just means "compute the sum"

[glad sierra]

ye then the values needed are already given
@eager crater would it be too much to fill in the Sn formulae using the values given? for 1 and 2?

[eager crater]

thank you so much dude

[eager crater]

sadly i havent payed attention in class for a really long time and have no context at all, ill have to try and read the notes and see if i can figure that out

[glad sierra]

hmmm
i hope you're doing okay
would suggest going to khanacademy to learn these given you haven't understood class

[ember kernel]

Ohhh yeah I remember now the Sn value thing

[eager crater]

thank you, im struggling but im gonna try my best, ill give khanacademy a try

thank you guys :)

[glad sierra]

oh lmao

@ember kernel second one is geometric ye?

[ember kernel]

Yeah I did 1 by hand, then 2, and then 1 again using the Sn formula

[glad sierra]

ah

[ember kernel]

@eager crater Check @glad sierra 's anwser. I didnt't compute the series using the Sn formula

[glad sierra]

https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:series/x9e81a4f98389efdf:geo-series/v/series-as-sum-of-sequence

aight that was fun
now back to my math xD
thanks @ember kernel
all the best @eager crater ❤️

[ember kernel]

Maybe I should sleep now. I've got a huuuge exam 34h from now, which I definitely don't feel ready for ✌️ 😅

[eager crater]

u guys are great, best of luck to you both

[glad sierra]

all the best 🙂

[ember kernel]

Thanks to both of you ! Have a good day/night

[ruby pawn]

I'm really confused on this

[ruby pawn]

nvm i think i got it

[covert anchor]

How do I find the shortest distance from r to qs

[cobalt rapids]

context?

[lofty geyser]

Should you use Mathematical Induction?

Under what topic was this question asked?

Okay, I will try

When is deadline?

[cobalt rapids]

how?

[lofty geyser]

Did you go through explanation

I remember something about using Discriminant to check for the intersection

[cobalt rapids]

i didnt understanding the explanation

[ember kernel]

The explanation looks detailed enough, though I don't get why it used ax² = -bx -c
Due to the root x = 1, we know for fact that 1².a + 1.b + c = 0, thus a = -b-c. But the explanation states ax²= -bx -c as if it was true for all x, which it isn't. (Or maybe it's just for x in the set of roots of the first function)

Could you send the complete explanation pls ?

[cobalt rapids]

they dont use the x=1 being a solution anywhere in the explanation

@ember kernel

[ember kernel]

Yeah, the explanation seems wrong to me regarding what I mentioned earlier. ax² + bx + c = 0 looks used for all x, while it's only valid for x = 1 (and the second unknow root)

I'll try it on my graph calc, give me a second

Ask your teacher about it, because I may have misunderstood the question (because I can have zero, one, or two roots depending on the value c, but that's not an available answer in your test)

[cobalt rapids]

okaay , thanks for the help

[crystal mural]

There was a question here about 3x+4y both x and y divisible by 7
was it solved?
I'm really interested in finding the solution but I cant find the messages anymore for some reason

[covert anchor]

22 iii

how is this possible

[supple island]

hint: ABCD is also a square

[solar socket]

can anyone help me with this?

@ember kernel

[dreamy lintel]

@solar socket (1.) slope triangle (2.) differentiate (3.) just use your functions that u know

(or use the graph but idk if this is allowed for this exercise)

[solar socket]

Thanks so much. I got the 1 and 2 question but im still confused on 3

[dreamy lintel]

just spend some time thinking about it, if you still have problems ask again for some advice

[solar socket]

alright thanks !

[dreamy lintel]

np

[ember kernel]

It looks like someone was faster than me ^^

[solar socket]

If you dont mind im still confused on the 3rd problem on that sheet :)

[dreamy lintel]

use your x values on the function that is given

i hope that helps ^^

[ember kernel]

Since ABCD is a parallelogram, you know for sure that you should have the following properties :

• distance between B and C = distance between A and D (opposite sides have same length)
• [AD] // [BC] (opposite sides are parallel)

This leads to only one solution : [[[SPOILER of the solution below, give it some thought before reading it]]]

---

The vector [BC] IS the vector [AD] ⇔ [BC] = C-B = [AD] = D-A
Which gives you D = A+C-B = (3 ; 11) (in terms of x and y coordinates)

[solar socket]

So we would plug in f for -5^2 like this?

[ember kernel]

f(3) is the number you get when you replace x by 3 in the function f, which consists in the segment [AB] and the function y = (x-5)² united

[ember kernel]

That's not quite that, because you computed -5² * 3 instead of (5-x)² = (5 - 3)² (with x = 3), which is completely different

But you got it right about replacing x by 3 😀

[solar socket]

Oh i see what i did wrong now! il try it again. thanks :]

[ember kernel]

You're welcome !

(Also, -5² = - 5*5 = -25, while (-5)² = 25. Parenthesis are important when computing a square that includes a negative value)

@solar socket

[solar socket]

gotcha

[solar socket]

sorry for asking so many questions but is this correct?

[dreamy lintel]

why are you multiplying 4*3 at the end ? what is your idea behind that ?

[ember kernel]

@dreamy lintel is right, you already used the value 3 in the parenthesis (5- 3)²

Put simply you get that : f(3) = (5-3)² = 2² = 4 😀

And that's all for f(3), you just need to do the same with the other values

[solar socket]

Oh i understand now! thank you both sm <3

[ember kernel]

You're welcome =D

[alpine escarp]

can someone help me prove this

[ember kernel]

Is it linear algebra ? If so, are a, b, c, a', b' and c' vectors ?

[alpine escarp]

it's boolean algebra

a,b,c are variables and a',b',c' are their respective complements

[ember kernel]

I've never studied that, but I guess you could use these expressions, and develop them just like you would for linear algebra

[alpine escarp]

aright thanks for trying

Turns out the question isn't symbolically correct

lol

[ember kernel]

Oh ok haha

I was trying to solve this by hand

[alpine escarp]

yea same

[ember kernel]

(got nowhere tbh xD)

[barren verge]

Can someone help me with math

Geometric progression

[zealous flume]

Anyone here with knowledge of ,Regression Analysis,?

[left knoll]

for (ii) why did they use sin?

[peak eagle]

depends on the question 🤷🏼‍♀️

[left knoll]

is it because cos(90-theta) = sin? and youre actually finding the angle between the line and normal? if anyone knows i’ll greatly appreciate it

[ember kernel]

By definition, (1,1,2) is normal to the plane pi

As theta is the angle between the normal vector of the plane pi and the x-axis, the angle between the plane and the x-axis is 90°-theta, thus cos(90-theta) = sin(theta)

(You get the vector (1,1,2) using the coefficients of x+y+2z=1)

[humble bobcat]

RandomThought: The difference between diameter and radius is radius : )

[eager crater]

is anyone good with normal distribution?

[gray walrus]

@eager crater not sure if this is enough to help but here. I'm happy to explain more about normal distributions and the empirical rule if you like

[supple igloo]

can anyone help me with guassian elimination, I know how to do it like how to set it up and that I need to use like adding and subtracting to get zeros in a triangle but I can't seem do come up with the operations to do it, I know there isn't any rules that works everytime but do you have any tips on how to do it

like solving systems of equations with matrices

[ember kernel]

The is indeed a rule tha works everytime

Give me a few seconds

[granite crow]

@supple igloo sure thing, do have any particular questions?

[ember kernel]

Sorry for my bad handwriting, I've just waken up from a rough sleep

[ember kernel]

For rule 2 : do it before starting your Gaussian elimination process, as it will also affect the items on the same line and on previous columns (which you already turned into zero). You don't want to waste time making these previous columns zero again

[tiny tiger]

Can someone solve it?

[left knoll]

5^(x^2)=5^(2*(3x-4))

x^2-6x+8=0

[tiny tiger]

thanks man

[left knoll]

I don’t get it lol

Do they mean the negative is basically squared ? Like - x -

= + ?

idk

[ember kernel]

Yep, you can actually suppress the - before (x-3), because (-(x-3))² = (-1)² * (x-3)² = (x-3)²

[left knoll]

Thank you !

[ember kernel]

You're welcome !

[left knoll]

@ember kernel ,for more clarification,whenever there’s a negative and a square,we can immediately cancel the negative,yes?

[modest compass]

Yeah, that goes for any even power btw

[left knoll]

Thank you ! 🥰

[ember kernel]

As long as the negative is in the square though ! -(x-3)² = -(x-3)² and you can't cancel the negative

[simple magnet]

Please help 🙏

It gives me 33.3º as a result, but I don't know if it is correct

[left knoll]

I found x=50°

But I am not sure

I'll check my solution

My answer is not true

[covert anchor]

23 b

what equation do i use

[brittle trellis]

can anyone explain how to do sine rule and cosine rule

[inland oracle]

Translation: Determine the next equation

I can't solve it:(

[simple magnet]

Give me this answer

[inland oracle]

thanks so much !!

[upper mountain]

pls help me!!! :C

[dreamy lintel]

maybe try sth like (z^2)^250 or (z^4)^125 this often solves problems like this

[upper mountain]

thanks a lot!!! 👉 👈

[dreamy lintel]

did it work tho ?^^

[upper mountain]

yes uwu

[dreamy lintel]

what do you mean ?

[normal trail]

guys i need help with this differential equation right now if possible and thank u

[left knoll]

Do you need the third derivative with respect to X?

[ember kernel]

I'll answer the unsolved questions when I get home @simple magnet @covert anchor@normal trail

Give it 40mins + solve time

[normal trail]

no

[ember kernel]

Do you need the real or complex solutions ?

[normal trail]

real

[ember kernel]

I'm on it

[normal trail]

thank uuu

[inland oracle]

Translate: Graph the following complex numbers on the Argand plane and write each in binomial form

[potent pewter]

Could someone help me with this?

[ember kernel]

You could use a Taylor development for that

[potent pewter]

How do you do that?

[ember kernel]

For a) :(3)60° means that a point is on a circle of radius 3, and at an angle of 60° anti-clockwise of the Real axis

For b) : It is very useful to know that e^(ik) = cos(k) + i*sin(k)

[ember kernel]

What grade are you in and what math topic are you studying right now ?

[potent pewter]

I’m in 6th grade and I’m studying decimals and some other stuff as well

I’m taking this test so I can learn more for my upcoming grade

[ember kernel]

Oh ok then a Taylor development is way too difficult for you.
Then you could give lower and upper limits to the square root of 7 (i'll denote it as sqrt(7) )
Example : you know that 4 < 7 < 9,
thus sqrt(4) < sqrt(7) < sqrt(9)
So you know that 2 < sqrt(7) < 3

[potent pewter]

Oh ok

[ember kernel]

If you settle with that level of precision, you can estimate sqrt(7) as 2.5 (the mean value of 2 and 3) = 5/2

But if you want to be more and more precise, you can try to find upper and lower limits that are closer to sqrt(7)

[potent pewter]

Oh ok

Thanks a lot dude 😄

[ember kernel]

But it's tough indeed because, for lower limits you have to find fractions that are between 4 and 7 AND made of such numbers that their square roots are easily computable

You're welcome

[dreamy lintel]

😄 well u could teach a 6th grader the taylor development 😄

[ember kernel]

That seems odd to me. I had never heard of differentiation until I was like 15, and he/she must be 11 or 12

[dreamy lintel]

nah im joking ^^

[ember kernel]

Haha

I mean I could teach him

Not sure he'd understand though

[real totem]

smn help pls

sorry my shit is in dark mode for some reason

[ember kernel]

I'm sorry I couldn't go further. I'm a master these but my brain is jelly, I've had a huge exam today

[dreamy lintel]

(a) i'm not sure what's missing in that diagram, maybe the numbers of the groups ? (b) find out how many students are in the 2 circles, hint: you know 12/20 students with blonde hair have blue eyes (same for 12/18 students with blue eyes). (c) use what you found out in (b)

[real totem]

in a its just that there are 50 students when we add up the numbers

but there are suppose to be 40

[ember kernel]

Indeed

Because the ones in the very center of the Venn diagram are counted twice (because they have blue eyes AND blonde hair)

For (a), you know that 12 students have blue eyes and blonde hair
You also know that a total of 18 students have blue eyes. That leaves a total of 6 students that have blue eyes BUT NOT blonde hair

[limpid vine]

so is this correct?

[real totem]

same question btw

we both in the same skl

[limpid vine]

the numbers for blue eyes and blonde hair are switched ^^

[ember kernel]

Well no, because what your diagram says is that 8+12 = 20 students have blue eyes, and 6+12= 18 have blonde hair

Oh ok

Yeah then it's correct if you switched the names

[limpid vine]

ok thanks

[ember kernel]

You're both welcome

[left knoll]

What do you mean by ‘in the square’

😅

[ember kernel]

(-2)² is the square of -2 and is equal to 4
-2² is the opposite of the square of 2 and is equal to -4, because the minus sign is not multiplied by itself

[normal trail]

nah it's okeeey , thank u sm for ur help

[ember kernel]

You were asking me if you could immediatly cancel the - whenever there was a - and a ², my answer is no. It totally depends on whether the - is included in the parenthesis that the ² affects

That' what I meant by "in the square", I didn't know how to express it in another way

[left knoll]

oh alright so
-(2)^2 for example,the - does NOT canceled,but for something like
(-2)^2 the - get cancelled

Oh

Lol

I mean that makes sense
can I just put another bracket for help (let me demonstrate)

[weary arrow]

Yeah that works fine

[potent pewter]

Is this correct?

[valid elm]

but if the question gave it strictly as -(9-3)^2, u can't just add brackets and move the power to [-(9-3)]^2 as that completely changes it

[weary arrow]

Yep!

[ember kernel]

You got it !

[left knoll]

alright,got it,thanks guys!!

[ember kernel]

You're welcome !

[potent pewter]

Help 😭

[left knoll]

Please someone good at maths help me out

[weary arrow]

OK it's a bit tricky, but you basically have to find the diagonal of the bottom of the box and then use that diagonal to find the longest diagonal

[left knoll]

please someone help

[weary arrow]

Lmk if the explanation was too unclear and I'll try to break it down step by step

[timber galleon]

((X*y)/2 ) × sin 60 =( x+y)sqrt(3)

[ember kernel]

Compute the length of all diagonals possible in the box, then compare

[left knoll]

i got that bit but how do i show that 4x+4y=xy

[weary arrow]

Try to use that expression to show it, multiply both sides by 4, and find out what sin60 is

[left knoll]

omgg thankyou soo muchh!!!

for part b would angle abc be 90 degrees?

[timber galleon]

Google agrees

[left knoll]

lmao thankyouu

so does that mean u would use the cosine rule to work out what cb is then just trig to work out x and y?

[timber galleon]

I think you would have to insert 4y/(y+4) instead of x into the cosine thing

So you have only 1 variable

[left knoll]

oh okay

so what like a^2 = x^2 +y^2 - 2 (x)(y) cos (60)
= x^2 + y^2 - 2xy (1/2)?

[timber galleon]

Oh thats the cosine rule xD

Wait if the angles are 60 30 mybe a=2x

[left knoll]

ohh lmao im so bad at maths 😭

[timber galleon]

Is there solutiin

Solution

[left knoll]

no

i couldnt find one

[timber galleon]

If u use sine rule thing u get y/sin90 = x/sin30 right?

[left knoll]

ye i think so

[timber galleon]

Then u have Y=x/sin30 and Y=4x/(x-4)

If that is good just insert 1 equation into other and u get x=6 y=12 but i might be wrong

[teal jungle]

pls help

[ember kernel]

I tried it, here's where I got

@teal jungle @simple magnet

Couldn't finish though, I got interrupted

[left knoll]

ohh yeahhhh no that is right

tyssmmmm

[simple magnet]

It is asking for the angle x

i have something similar, but i'm not sure if it is correct

[ember kernel]

I know, I forgot about sine and cosine rules

[simple magnet]

You can check?

[ember kernel]

And didn't bother to look it up tbh so I git stuck ^^'

[simple magnet]

ok ok, thanks for the try 😊

[tiny tiger]

can someone show me how to do this?

[ember kernel]

There is a trigonometry formula for that :
sin(a-b) = sin(a) cos(b) - sin(b) cos(a)

@tiny tiger

[tiny tiger]

okay thanks i will try it

[left knoll]

is anyone here good with statistics? i'm so confused rn

like wtf is even "costco sampling"?? does that even exist?

[weary arrow]

I think Costco sampling is a fake alternative added for fun

[left knoll]

bruh

[pseudo spindle]

lmao

[left knoll]

Yo anyone got any notes on statistics they would be willing to share

[clear wave]

https://drive.google.com/drive/folders/1pJwGoKJOimQNmLabaIuHGu6b-lo95GwB?usp=sharing

[left knoll]

dude you're an angel thank you so much ❤️

[covert anchor]

How do I find k

I believe I need k to form the equation

[left knoll]

first u use A and B to find the equation of the line

so u can use m = (y2-y1)/(x2-x1) to find the gradient of the line

then u use y2-y1 = m(x2-x1) to find the equation of the line

then from that equation you have just found, you sub y = 13 and x = k and rearrange for k then voila you have your answer

[covert anchor]

Do u mind explaining this ?

[left knoll]

so first, does the first step make sense? finding m?

[covert anchor]

yes i got graduient of 5

[left knoll]

once you do that, you sub m=5 as well as only ONE of your points into y2-y1 = m(x2-x1)

i probably should have written the equation as y-y1 = m(x-x1) instead

so for example using point A:

y-8=5(x+3)

[covert anchor]

y-y1 = m(x-x1)
I have nerver learnt this b4 hahha

[left knoll]

ahh okay

so you know y = mx + b?

[covert anchor]

yes

b being y intc right

[left knoll]

so we use y = mx + b if we know the gradient and the y intercept of the line

but if we don't have the y intercept

and instead lets say we have the gradient and one of the points that lie on the line, we use y-y1 = m(x-x1)

so in this case we know two points on the line, as well as the gradient, but we don't know what the y intercept is, so we use y-y1 = m(x-x1)

if you look carefully, you will notice that you have actually used this equation many times before

it is the same as m = (y2-y1)/(x2-x1), but it has been rearranged: (x2-x1) has been moved to the other side

[covert anchor]

aight

[covert anchor]

so using this how do i find k

by subbing k and 13?

[left knoll]

yep :)

[spice garnet]

hello~

um

I need to make the equation 2(3x + 1)² = 0 in the form of ax² + bx + c = 0, is the answer 6x² + 4 = 0 right?

[lusty needle]

Not quite.
The first step is distributing the exponent: 2(9x^2 + 3x + 3x + 1) = 0.
Then the 2: 18x^2 + 6x + 1 = 0

[spice garnet]

ah

thank youuu

[lusty needle]

Np!

[spice garnet]

sorry

i have another question

i dont get how 2(3x+1)^2 becomes 2(9x^2+6x+1) = 0

[left knoll]

Using (a+b)^2= a^2+2ab+b^2

(3x)^2+(2)(3x)(1)+(1)^2

[spice garnet]

im asian yet im so bad at math lmaoo

[left knoll]

9x^2+6x+1

[left knoll]

everyone is bad at maths until they practice enough lol

takes practice

[spice garnet]

ill do my best

[left knoll]

just memorise this (a+b)^2= a^2+2ab+b^2

[spice garnet]

thank you

[left knoll]

np :) gl

[covert anchor]

29iii

how do i do 29iii

[pastel helm]

It's kinda blurred

[acoustic delta]

Can you send this task in a little bit better quality

[supple birch]

u can use determinant to get the area.

[covert anchor]

How ?

[supple birch]

is giving solutions allowed? idk im new here

[covert anchor]

no like guide me

[supple birch]

"Finding the area of a triangle using the determinant of a matrix"-look it up in google..
super easy

[left knoll]

yo i feel like determinants are too complex for this level of maths

[supple birch]

k

[left knoll]

definitely the easier way of doing it but i don’t think they know matrices

[supple birch]

find distance between A and B, and the distance between E and AB line..

u have base and height now

[vernal warren]

Yoooo

Please give solution to this

Ques 42

[edgy crag]

How do you do this i tried looking up videos but they didnt really help much, can anyone explain please? (#46)

[vernal warren]

Here is your answer

[supple birch]

Ur ans is C

[vernal warren]

Can you please send solution or explain it ?

[supple birch]

x will be positive and negative iff sqrt(a^2-a-1) > (-a-1)

solve the inequality and u get x<(-2/3)

[vernal warren]

Okk
Thank you so much

[edgy crag]

Omggg thank you so much

[green root]

hey there I think there's a mistake with the roots in the end, should be 5/2 instead of 5/6

[edgy crag]

Ohhhh okay thank youu

[vernal warren]

Ohh yess
Sorry
I didn't saw it
In hurry I guess I messed up

Thanks for the correction

[clear wind]

send me your math guys

i can solve it all

😆

[green root]

no worriess it does happen sometimes hahaha

[fierce bone]

first derivative of x^2- y^2+4xy+20= 0

can someone help me?

[ember kernel]

A differentiation (=derivative) has to be regarding one variable only. Here, you have two, so if you want to differentiate regarding x, just consider y as a mere constant, as if it was a number and not a variable

[fierce bone]

ye i forgot to move the dy and dx

lmao

thankyou rian and quentin

[worldly copper]

Hello, may someone help me with this

[worldly copper]

I get this but I’m not sure if it’s true

[ember kernel]

Give me a minute

[worldly copper]

Thank you, fellow

[ember kernel]

I have no idea how you proceeded because we have different expressions for x, but you were right because we have the same solutions

@worldly copper

[worldly copper]

Yeeee thank you very much for your time 🙏🙏🙏 have a nice day

[ember kernel]

Thanks, you too !

[clear wind]

it's really interesting to see math homework from you guys

cause it's totally different from what i am taught

[modest ice]

Yall what would be the square of 3200 picometres Coulomb?

[supple island]

can't you just use a calculator?

[supple birch]

picometres coulomb doesn't make sense

[ember kernel]

1 [pico-unit] = 10^(-12) [unit]

So (3200 [pico-unit])² = (3200×10^(-12) [unit])² = 3200² × 10^(-24) [unit²]

@modest ice There is you answer

[ember kernel]

Actually, there is such thing as metres coulomb [C.m], they quantify dipole moments (mostly used to determine the polarity of molecules in chemistry)

(It's officially called coulomb metre, but it describes the same thing as "metre coulomb" due to the commutative property of multiplication)

[supple birch]

haven't studied dipoles for years... so meters coulomb didn't ring any bell

[modest ice]

Actually I wanted to see sth 🥲

Ahhh thankssss for this one 😭 I was just confused coz here we had to double the charge so it felt strange how they didn’t end up doubling the picometres ( I didn’t had the picometre farad [from the capacitor] in my mind) and thought they didn’t end up doubling the picometre from the charge but now it’s confirmed that u have to double the picometre and in this particular question it just got cancelled with the picometre of the capacitor

[ember kernel]

Also, 3200 pC is 3200 pico-coulombs, not pico-metres coulombs

@modest ice

[modest ice]

Ahh wait I keep messing up the units 😭 I’ll keep that in mind thanks again

[ember kernel]

That's, fine, practice makes perfect

[subtle parcel]

anyone here who know REAL ANALYSIS, hmu?

[ember kernel]

What do you mean by real analysis ?

[north trellis]

Could someone help me with this?

(1) 2x+3y=20
(2) 3x-3y=5

[ember kernel]

In linear algebra, you have two ways of solving this

[vernal warren]

You can do it by elimination method

[ember kernel]

((A)) Take one equation, and isolate a variable. Example : in (1), you isolate x, which gives you x = (20-3y)/2. Then, in (2), you replace x by the value you've just found. That gives you the equation 3*(20-3y)/2 - 3y = 5. From there, you can isolate y to get its value, and come back to the expression x = (20-3y)/2 to get the value of x. Solved :)

((B)) You use a linear combination of the equations (lines) to simplfy one of them.
From :
(1) 2x + 3y = 20
(2) 3x - 3y = 5
You can do the linear transformation "(2) becomes (1)+(2)", which gives :
(1) 2x + 3y = 20
(2) (2x+3y) + (3x-3y)= 20 + 5
<=> 5x = 25. <=> x=5
(You eliminated y from (2))
From there, just use your newly-found value of x in (1) (the untouched equation) to get y as well. Solved :)

[covert anchor]

For question 9 how do I do it

[subtle parcel]

real analysis is a subject in itself

[vernal warren]

Which one is ques 9
Upper one lower one ??

[covert anchor]

upper

sorry

[left knoll]

What grade math is it??

[covert anchor]

why ?

my grade may not be lie ur country's

[left knoll]

Still tell

[covert anchor]

err my country does not go by grade

[left knoll]

Then.. class?? R u in school??

Whats ur country india?? Or European country??

[covert anchor]

Singapore

[supple birch]

in LHS its e 3rd degree polynomial,,
so Q(x) must be 1st degree polynomial..
let Q(x) = 4x + C
u will get three equations from the coefficients.. solve them to get A, B

[ember kernel]

I get that, but what does it consist in ? I might have studied it under a different name

Unless it's college level stuff

[left knoll]

How is Q(x)=4x+C??

[covert anchor]

can i sub in a number

like 3 or -2

[supple birch]

Coefficient of x^3 is 4 in LHS...so in RHS the coefficient of x^3 must also be 4

[left knoll]

Thx

[subtle parcel]

It's University maths. Real analysis is about proofs of calc with epsilon delta

[vernal warren]

Damn
Then I am out
I can't help
I am in just 11th grade 😂😂

[grand blade]

If im not wrong in Singapore our GCE "A" levels are comparable to high school/college before university, and the alternative route is in polytechnics for a diploma. Might be wrong because im not too sure how high school and college works in other countries

[ivory pumice]

That is the shortest way I can think just put x=3 and -2 respectively and calculate values of A&B

No need to find Q(x)

As it is an identity , it will be true for any value of X

[left mountain]

It’s exactly the same in the Uk. Basically in year 12 and 13 (College/Sixth Form) you take your a levels. Then you go to university (optional)

[left knoll]

@vernal warren u from india i guess?

[vernal warren]

Yess
How did you guess??

[analog wagon]

plz solve it

[ember kernel]

Yeah I've studied that! But I was just too bad at it sry 😅

[subtle parcel]

Okok. I don't have a Q. I want to know how to study that?

[left knoll]

I can give a hand if you wish

May we go in private, either i can make a list here 🙂

[subtle parcel]

@left knoll ok dm me

[ivory pumice]

e^(-lna/b)?@analog wagon

[ember kernel]

Sry for thumbsdown, I had forgotten that sec = 1/cos

[ivory pumice]

Np

e^(-a/b) is wrong btw , I rechecked my calculation , now my answer is e^(-lna/b)

I think that is the answer

[analog wagon]

e^(-a^2/b^2)

[ivory pumice]

Hmmmm

Lemme check again then

Is it a^x or ax?@analog wagon

[slender kelp]

anyone here studies kinematics in additional math

[ivory pumice]

Idk what I am doing wrong ,am getting e^-(a/b)

Again

@analog wagon

[tiny tiger]

I need help with this one

[mental snow]

for gradient you'll need to find dy/dx and input the values of the given points into the curve u get

[tiny tiger]

Okay thank you man

[mental snow]

😄 have a nice day 😄

[lost galleon]

hi

The answer is not important, but the method of solution..Anyone here can explain🥺

[fervent tide]

have you tried using l'hôpital? (ie. taking the derivative of the top and bottom of the fraction)

[modest compass]

Anyone mind explaining what limits actually are, what they do and how they're used pls

[edgy crag]

Can someone help me with this one?

[modest compass]

b²-4ac tells you how many roots a quadratic has, for a b²-4ac has to be less than 0, for be b²-4ac = 0 and c b²-4ac > 0

I'm not too sure about d though

[edgy crag]

Ohhhhhhh ok thank you

And its fine thank you for helping thoughh

[lethal crater]

A spotlight on the floor illuminates a wall 12m away.

If the shadow of a 1.7m tall man, walking from the reflector towards the building, decreases at the rate of 0.9m/s.

What is the variation in the distance that the man travels when he is 5m from the wall?

I don't know if it is well translated, sorry

[left knoll]

Hey guys

can anyone help with a weird math problem

it seems super weird and I am not sure what a symbol means

[worthy patrol]

9?

[stable hawk]

9

[spice stump]

I’m dumb

[mental snow]

I think the answer should be D. does not exist

cause left hand limit and right hand limit are not equal

[ivory pumice]

Yep does not exist

[ivory pumice]

For D part , discriminant should be >0 and it should not be a perfect square

[queen sphinx]

Can someone help me with this question I'm writing my exam on monday

I already have exercise A but I have no idea how to do B

Thanks a lot!!!

[analog wagon]

thnx for the hlp!

[glass matrix]

guys ik im dumb

but how does that equal 46?

i got 36 which was then minussed by the 10 which is 26

ohh

im dumb lmfao

my bad

heeheeee

[cloud girder]

hello can anyone help me? im major struggling

[ivory pumice]

Np, lemme try last time again , I might be doing something wrong , I will let you know if I get the answer

[ivory pumice]

Oh I got the answer lmao

@analog wagon do you still need solution?

[lost galleon]

thanks

[green root]

Hello, I wanna ask for part (ii), in the mark scheme, where does the 12.5 in the third line comes from?

[quaint bone]

its the vertical component of your starting velocity

so 25m/s * sin(30°)

@green root

[green root]

tqsmmm!!!

[tiny tiger]

Find the value of n

Plz help me

[left knoll]

@tiny tiger

[tiny tiger]

Thank you man

[left knoll]

U re welcome

[glass matrix]

could anyone explain this to me 🙂

[glass matrix]

ooooh thankuu ❤️

[left knoll]

You’re welcome:)

[barren seal]

I'm really lost at differentiating this could someone help me with the steps?
v = 20,000e^-t/10 differentiating v with respect to t

[modest compass]

e^kx differentiates to ke^kx

[barren seal]

thanks a bunch

[left knoll]

Could someone help me with this sum

[left knoll]

Thanks

[glad sierra]

https://www.youtube.com/user/jbstatistics

this channel is great for statistics!

[tiny tiger]

Can someone plz help me with this

[weary granite]

@haughty sinew 1 + 1?

[untold relic]

Yep it’s good can you edit us out of your post

[tiny tiger]

thank you man

[eager crater]

could anyone help me with these two?

[analog wagon]

umm yeah!

[lost galleon]

Is there an easy way to memorize the sine and cosine of the famous angles

[cobalt rapids]

it becomes like remembering 2+2=4 after a while, but i think i used this when i first tried it 3-4 years ago

https://www.youtube.com/watch?v=jI81WXyFrL0

[cobalt rapids]

for the Q3, the '+14' means it is a std. sin graph (with amplitude A) just shifted upward on y axis by '14 units'

now since y=14 is the mean position then max value is 14+A=37

which means A=23

for minimum value subtract amplitude form mean position ie. 14-23=-9 which should be the answer

[eager crater]

oh dang it wasnt as complicated as i thought, thank you!!

[cobalt rapids]

for the first one this is coming out as my answer, it could be converted to sin tho. lmk if its right and ill tell you the process

[sharp ferry]

You know the best way I've found is to literally just derive them

When you derive them yourself it stays in your memory

And if you know where it comes from you can p much derive it again if you forget it

I hope my famous angles you mean 60° ,30°,45° ,90° and 0°

And also 53° , 37°, 18° and 72°maybe,

[ripe hamlet]

Help pleaseee

[supple birch]

7

[dreamy lintel]

I got a complex Analysis Problem: I got a polynom P(z)=z^4+6z+3 and the question is how many roots are in the circle around 0 with the radius 1.
It would be cool if someone could help me

[ripe hamlet]

Thank you

[lapis yoke]

can you help me?

[modest compass]

What exactly are you looking for?

[obtuse mural]

We know that a>0 because the concavity of the parabola faces upwards. Furthermore, since the parabola continues down the x-axis, we have that it cuts the y-axis into any number y' such that y'<0. So c<0 (c is exactly where the parabola will cut the y axis). And since when cutting the y axis the function keeps decreasing, b<).

[lapis yoke]

it's how i can get the answer

[obtuse mural]

oh man i showed you directly the answer

[lapis yoke]

thanks a lot

[modest compass]

Oh it was a multiple choice question 😆 i didn't clock

[obtuse mural]

I also need math help

Given a triangle ABC, construct A'B'C' equivalent to ABC knowing two sides of A'B'C'. This is the question, can somebody help?

[tiny tiger]

Can someone show me how?

[obtuse mural]

first part

[fast igloo]

ur handwriting is beautifuk

[floral jasper]

but (x^2)^(1/2) = |x|...?

[glass matrix]

what does the arrow mean ??

[mental wraith]

that the two statements are equivalent

[vernal warren]

Yo
a < 0 because parabola is opening downward

Am I right?

[left knoll]

similar

[tame surge]

No.6 please

[silent snow]

dy/dx karo and 2e rakh dena dy/dx ke jagah uske baad find kar lo x ka value and jo x ka value aayega usse y nikal lena

[tame surge]

Like this?

[light snow]

anybody here can help me with this integral? I can't figure it out

[left knoll]

yes ok so

basically what u want to do is rewrite it in a form that would fit the bottom

gimme a moment i'll show

@light snow

Check my calculations but shld be right

[left knoll]

@light snowhere

[light snow]

thank you so much! I really appreciate it

[left knoll]

the idea is there either way if i messed up the calculation

no problem

btw, another way to do this is to perform long division

[light snow]

seriously thank you. I started as you did, splitting 8sigmaD into 12sigmaD - 4sigmaD but then I didn't "partial recollect" 4sigma/Pe right at the second step (third line) of your proceedings

[light snow]

yes you're right

[left knoll]

@light snowhere

[left knoll]

eyy, that's still good tho

long division is a bit easier tbh

but i mean it's good to have more than one method in ur toolset

[devout cipher]

Çözebilecek var mı?

[ember kernel]

Can't understand but I'd try to use the chain rule : dy/da = dy/du * du/dk * dk/da

[devout cipher]

for u = -3

dy/da = ?

[queen rover]

uhm I seem to get a non real answer

like +/- j*72

u=-3->k=0->a=+/-sqrt(-1)=+/- j

[silent snow]

Yaa

[fair trellis]

Please could someone help me with this

[supple birch]

take the 7sin(b) to right side and the 8sin(d) to left side

square the eqn

do the same for the other eqn

then add those two equations

[fair trellis]

Got it
Thanks!

[lost galleon]

There are many ways to solve the limit..how do I know which one to use (analysis, quadratic conjugate, etc.)

How do I know the fastest way..without solving one method, then discovering that it is wrong, then returning and solving another method, and so on (a waste of time)

[left knoll]

I would say with experience

you simulate many methods at the same time in your head

I do like that i have a view of the limit and think of the 3/4 methods up to me, and i start by testing at the sametime each of them, if i failed i missed something ; it's more about experience and fast thinking than pure math (most of the time)

[lost galleon]

😍

[lost galleon]

Your words are true... but in the exam... the second counts

[uneven cloak]

Anyone? 2+2÷2= ‽

[floral jasper]

3

[north trellis]

Can anyone help me with this problem?

Bruna had a certain amount of money with her when she arrived at the mall. She spent two-thirds of what she had to buy a sandwich. Of what was left over, Bruna spent half on a movie ticket. What was left was US$20.00. She then used the amount she had to buy a book. Write an equation for the total amount x that Bruna had on her.

[pallid mason]

Can someone help me with some ambiguous triangle problems?

[steel plover]

can someone explain how v'/v^2 is equal to -v^-2 * v'

[ember kernel]

1/x^k = x^(-k)

Just like that

[steel plover]

oh yeah thanks!

[ember kernel]

I'm kind of tired now so I might've misread something, but this looks like the answer

I hope Bruna enjoyed her $80 sandwich

(Btw Movie is the money Bruna had before buying her ticket)

[north trellis]

Thank you!

[quartz maple]

Any one know how to solve for x or know how to solve this (if it even exists) ?

[icy umbra]

can someone please please please explain this

[icy umbra]

thank you so much. I really appreciate it

[left knoll]

You’re welcome

[crisp drum]

Can someone check this please?

[left knoll]

you have a mistake, when you do f(x+h) it gives 3(x+h)=3x+3h, and then the limit becomes 3h/h which gives 3, the correct answer

[crisp drum]

ohh i see, thank you so much!!

[left knoll]

Does somebody have any idea how to solve this? please, thanks. I am glad for any advice related to this type of problem.

[crisp basalt]

Can anyone solve this question?
Question:Prove the mean with the theorem.
Thanks.

[left knoll]

many many many thanks Seiren

[left knoll]

you're welcome ☺️

[abstract latch]

can someone please help me with this problem?? it's an implicit function problem that I have no idea how to solve

[north schooner]

let me know if this is correct

[ember kernel]

Use unknowns a, b, c, d as items of X. Then, compute both sides of the equation. This will give you an equalitu between two 2x2 matrix. For the two matrix to be equal, each of their items has to be equal as well. Thus, you have four equations (because 2x2 matrix have four items) and 4 unknowns (a,b,c,d)

Just solve the system of equation to get a, b, c,d, and therefore X

(Btw is "matrix" indeed the plural of "matrix" ?)

[abstract latch]

thank you so much I deeply appreciate it <3

[north schooner]

welcome :) i am glad i was able to help

[obtuse mural]

omg yes, i wrote it wrong @lapis yoke the parabola is facing down

[left knoll]

yeah so train like an athlete 🙂

[solid anvil]

can anyone help me with any of the 1 question

oh np

i got it

[analog wagon]

anyone?

lim n tends to infinity x^n/n!

plz solve this

[weak mortar]

it goes to zero

i dont know which rules you know

but the reasoning is that for large n n! is approximately n^n- something else

and for large n n^n will be larger than x^n

but i know that there are certain rules to check whether a sequence converges or not

and you can use those rules i tink

i hope i could help you with this

[analog wagon]

oh, i didn't know this rule earlier .. btw thnx a bunch!

I tried to solve it, n got x^n = -(-x)^n .. How to solve further?

[left knoll]

You substitute n with all the values and choose the one for which the equality is true, since theory says that a function is even when f(x)=f(-x). So n should be 2

[analog wagon]

this is not gonna satisfied by ny pos n gvn ans is opt 4 but a quantity under cube root can't be neg so how opt 4 is posible?

[fair trellis]

Why can't the quantity be negative?

[analog wagon]

oh, I thought it will turn out to be a complex number..thnx

[fair trellis]

After simplifying, we get (-1)^n=-1 ,so n should be odd

[left knoll]

Took pen and paper and it is indeed answer 4, and it can be negative since the root is from an odd number

I first read your solution as x^n=(-x)^n

[analog wagon]

yeah thanks a lot, actually I got confused n completely forgot that neg under odd powers are possible for real numbers as well

[left knoll]

I also had to google the theory as well 😂

[peak eagle]

for 0 it's (x-0) so in total you have (x-(-4)) (x - 0) (x - 3) = (x+4) x (x-3)

I am super confused why that given system (reading exercise) is linear. I doesn't make any sense to me because - sin(t) isn't linear.
side note: x'_1 = dx_1/dt and x'_2 = dx_2/dt
Anybody who may have an answer?

[peak eagle]

show me you solution till know per DM and I will look where you did mistakes @heady salmon

[left knoll]

maybe sin(t) is considered a constant?

[peak eagle]

thought so to but than they would say something like for t element of IR or not ?

[left knoll]

does it have to be linear? since it says to verify...

also, it doesn't mention that functions a_j,k have to be linear

[peak eagle]

Well normally my tasks are in German so I am confused if it's written in English.

[peak eagle]

that's true 🤔
that could be the answer
thx

[left knoll]

totally understandable, usually exercises that follow after such definitions are meant to give examples of such systems

[left knoll]

this could be a good source, it has several examples https://openstax.org/books/calculus-volume-3/pages/7-1-second-order-linear-equations

[peak eagle]

thank you so much! 🙂

[rose acorn]

1+4+9+16+...+400=? can anyone help me with this i forgot the formula

[left knoll]

use arithmetic progression https://en.wikipedia.org/wiki/Arithmetic_progression

[runic cloak]

Anyone here know power series?

[rose acorn]

❤️ ❤️

[oblique lintel]

URGENT if anyone is willing to help me out w some precalc i'd appreciate it sm

[gusty bluff]

@oblique lintel what do you need help with specifically

[rose acorn]

more detail plz

[oblique lintel]

any of these questions 🙏 i was able to answer them but i’d appreciate it if someone could give me an explanation!!

[gusty bluff]

For the first one, the domain would be all real numbers except -2,0,2

[oblique lintel]

and why is that hehe

[gusty bluff]

can't have 0 in the denominator

[oblique lintel]

got it

[gusty bluff]

if there's a 0 in the denominator it would mean it doesn't exist

[oblique lintel]

okay i thought so

tyy

[gusty bluff]

yea np

[left knoll]

I hope this can help you (last problem)

and x goes minus infinite, y ->0

and if x=0, y=0

[oblique lintel]

THANK YOU SO MUCH 💗💗

[covert anchor]

Hi

I have found t to be20 which is correct

But for ii what to do

[supple birch]

avg speed = (total distance travelled)/ total time

find the area of the trapezium and divide by 4t

[covert anchor]

Wait

Can I find the area of triangle first

[supple birch]

yes

[covert anchor]

Ok

So I have 300 for triangle

[supple birch]

it should be 4t..sorry

[covert anchor]

I have 300 for traingle

[supple birch]

and the rectangle?

[covert anchor]

2400

[supple birch]

how?

base is 3t for the rectangle

not 4t

[covert anchor]

Ok 2100

?

[supple birch]

yes.. thats the total distance

[covert anchor]

2100+300=2400

2400÷5t ?

[supple birch]

shouldn't the rectangle's area be 1800?

[covert anchor]

How

1/2 . Base . Height

[supple birch]

thats not rectangle's area my friend..

[covert anchor]

answer is still wrong bro

thats why i cant do this question

the answer is 18.75

[glad sierra]

https://www.symbolab.com/

super useful for math
covers almost anything I can think of

[signal pilot]

Hello guys, how to solve this problem: a natural number N is called miraculous if its prime factorisation satisfies

Need to find all miraculous numbers which are less than 2021

[karmic wyvern]

Questions 5 ,7&6

[pulsar turret]

I’m new to functions and I don’t understand clearly why D is the answer. Any help would be appreciated

[supple birch]

the smallest prime is 2...and 2^11 > 2021.. so the summation must be smaller than or equal to 10.. so u can brute force with the primes 2, 3, 5, 7

[north schooner]

put the value equal to f(x). Except option D all other will yield a negative value which can't be equal to x^2
if u don't understand feel free to ask

[pulsar turret]

Is this the right way? All answers are positive

[north schooner]

umm actually u don't have to put the values in place of x, u have to put it in the place of the function f(x)
do u want me to send u an image of the solution?

[pulsar turret]

Yes please, that would be really helpful

[north schooner]

give me a couple of minutes

[last echo]

when u solve it, the answer shud be 0
so 2=x^2+2
x^2=0
x=0
i think v need to solve it this way, not sure though

[last echo]

yay! i was correct ;)

[pulsar turret]

Yes I understand now. Thank you so much!

[pulsar turret]

Thank you

[north schooner]

welcome :)

[north schooner]

great 👍

[wind tangle]

hello

[left knoll]

please help :) especially with the first one

please ping me once you have a solution

[ivory pumice]

x²+1/x² = (x-1/x)²+ 2x(1/x) = 49+2

@left knoll

[left knoll]

I don’t get the multiplication part when doing (x-1/x)^2

And why do we put in in brackets?