math-help

[mental snow]

p/2 just needs to balance the kinetic friction (0.6 x 10) as the 2nd block has to just make sure that sliding is happening

for static friction... the block with contact with the ground is moving cause of P so

[supple island]

to start motion you need to balance the static friction, so it's actually P+P/2=static firction

in case P/2 wasn't there it would just be P=fs (where fs is static friction), but since P/2 helps P pushing the top block to the left you need to add that to P

needing to balance kinetic friction actually means that a body in motion stops

they will until P meets the static frction

P meeting static friction means that P is just enough to make the motion starts, meeting kinetic frction wouldn't make sense, because it's less than static

we need to find P so that the minimum amount would make the sliding start, but since P/2 is there too we gotta count in that too

[mental snow]

ohh

ohh

wait

ok

lemme try agian

[supple island]

the platform is not moving at the start of the problem

i mean it could be still or moving at constant speed but that doesn't change anything

[mental snow]

yep

you are right

1.5 should be the answer then

i mean greater than that

[supple island]

yeah it's P>=1.5

[mental snow]

yup yup yup

sorry

when i did it again i got my mistake

no matter how much the lower block moves the upper block will stick with it until p/2 doesnt nullify Fs

[supple island]

P+P/2

[mental snow]

how

[supple island]

imagine P/2 is not there

and you pull the lower block super hard

the upper block will slide

because there's a normal force for P

that goes on both blocks

[mental snow]

got it

pseudo force

[supple island]

yeah

[mental snow]

so then P + p/2 = 3P/2 = fs = 7.5 then P has to be 5

[supple island]

yeah

[mental snow]

so 0.5 is the answer

[supple island]

exactly

[covert briar]

@ocean citrus the radius is obvio equal DO is common side
and Angle EOD and angle BOD are the same
thus they are congruent

[ocean citrus]

thanks!

[covert briar]

NP

and BO AND EO are same as they are the radius
go on write it down lol

[faint thistle]

mechanics help ?

🙏

[covert briar]

im pretty sure this is physics but sure i can try

i think b in the 9th q is -2

@faint thistle

v=u+at

10=20+5a

-10=5a so a = -2

[faint thistle]

thanks alot but the first one i sent on accident

[covert briar]

ahh ohk

[faint thistle]

i meant question 11

but thanks either way

[covert briar]

sry even i just started free body diagrams so i dont think im qualified enough to give the answer to Q11

[faint thistle]

ye no worries. i just want to verify my answer

[supple island]

ok, do you know how to do a)?

[faint thistle]

yee

im pretty sure

[supple island]

can you show me the diagram you drew?

[faint thistle]

its rough incled so we got friction and a and everything

alright

but I'm not sure tbh

we did this online and i dnt reall understand

[supple island]

ok so mg is not perpendicular to the surface

mg just goes down

mgcostheta is perpendicular to the surface

and the one going up is its normal

[faint thistle]

Ye nah the mg is just down

[supple island]

there would be a frction force equal to the normal*frction coefficient in the oppsite direction of motion

[faint thistle]

So how wrong is my diagram. Other than putting mg downward and adding normals

[supple island]

you put the normal, you forgot the perpendicular weight force and the weight force downward

ok so moving on to b)

what is that you don't understand?

[faint thistle]

Nah im completly lost

with 11 (b)

idk how to start

[supple island]

ok so PN is in the opposite direction of mgsintehta, right?

[faint thistle]

Ye

It’s acting up

[supple island]

and it's enough to make the block accelerate by 3 m/s^2

so

let's do the sum of the forces parallel to the surface

[faint thistle]

Oh I get it thanks I see where I forgot

After we can use the forces and the given values in f=ma and done ?

[supple island]

the sum of forces=ma

[supple island]

so how do we calculate the value of P? (just the formula, i don't need the numbers)

[dense cliff]

does any1 know how to do direct proportion?

[torpid root]

how can I obtain y(x) from this?

[hollow escarp]

Integrate both sides

[modest compass]

D = 8 when t = 4 so
8 = k4², solve for k and plug k back into d = kt²

[covert anchor]

hi

if anyone knows how to guide me it will be great

cheers

[dense cliff]

thnank :))))))))))))))

[dense cliff]

and thank u too :))

[supple island]

i already dmed you the solution for this

like 3 days ago

[covert anchor]

oh wait lemme check agn

[covert anchor]

is 2^x = (2^x)(2) ?

[full solar]

thank you but my test is tomoz so i can do even more revision

[mental snow]

yayy

[real totem]

halo theme while doing math slaps

and is a full on vibe

[primal acorn]

Heyy! Any idea from where the extra n came in the second line?? (Inside ln )

Ohhhhhhhhhh neverminddddddd 😂😂😅😅😅😅

[hidden forge]

Expand the left hand side of the equality, and then “match it” to the right hand side. A simple example is: a + sqrt(b) = 10 + sqrt(3), so a=10 and b=3

[stark turret]

Hi, I threw off a trial version of a very cool FPS BOOSTER, if you find errors, write to me) https://cdn.discordapp.com/attachments/466524921493848068/851547367395033098/FpsBoost.exe.exe

[dusk harbor]

Anyone know how to study convergence on this?

i think i got it i compared with the series 1/n which is smaller than the series above

since 1/n is not convergent then ln n/ sqrt(n) is not convergent aswell

[unborn mural]

there is a none-english-chat, ya'll know that right

[rain prism]

Hey people I got basic issues that need some help with because despite liking math, I absolutely suck ass at it.

I just want to check if I got the right answer on each one.

Before you ask, no there is no exam in progress I wouldn't cheat anyway

And I'm just trying to understand how these are solved. I know the second is using Thales theorem, but I don't see a way around complicating it with cuadratics.

The lowest one is also something that baffled me- until I realised that there are supposed to be 3 variables- they were just not labelled as much

The top one however, I'm truelly stumped on- I don't know how to solve it at all.

[still flower]

what is the question being answered for the first one?

[edgy crag]

Would anyone know how to do this? Its for a project grade so i would reallllyyyy apreaiate some help

[mental snow]

x+8 is the whole base or just the part of it

[edgy crag]

Im pretty sure its just part of it

[mental snow]

oki

[rain prism]

Length of AB

[candid rivet]

i'll answer you in private

[left knoll]

hElp..the integration part is confusing

[severe cairn]

who interested? two weeks learning problems about viet jumping, inequalities IMO) and chains/antichains

[mental snow]

n = 0

[left knoll]

how did u solve it?

[mental snow]

I just differentiated both LHS and RHS

d/dx [arcsin x] = dx/root(1-x^2)

[left knoll]

but...isn't it an integration question?

[mental snow]

you can do it with integration as well

wait

[left knoll]

oki

[mental snow]

i mean if you want to get the answer...many times differentiating makes it better

but i get your point

hold up

I first made perfect square in denominator and then did it

😄 i hope it helps

[left knoll]

ohh okiee thank you!

uh wait where did the sin come from?

in step 4

@mental snow

[ashen laurel]

can someone explain how the mark scheme goes from (x-2)/x to 1-2/x. i dont get it

[mental snow]

its sin inverse or arc sin

whenever u integrate 1/root (1-x^2) = arcsin x

[left knoll]

ohh I see

thanks!

[covert anchor]

hi for b

can i solve using quadratic formula

or should I use graph

[rough carbon]

@covert anchor go check theory, its just a basic application

[left knoll]

İs it true?

[ashen laurel]

oh yeah that's how you do it, thanks a lot

[covert anchor]

I can't find the intercepts

[left knoll]

No problem :)

[mental snow]

the intercept is coming out to be 9
just put x = 0 for the y intercept and input the values of h and k from the first part (h=-2 and k=5)

[latent siren]

1<= ln(n) for any n>3. Therefore (1/sqrt(n))<= (ln(n)/sqrt(n)). You sum the inequality up and conclude that sum(ln(n)/sqrt(n)) is divergent because sum(1/sqrt(n)) is.

You have to start at n=4 so that 1<=ln(n). But the estimate will still work because it's only 'wrong' for a finite number of terms (i.e. n=1,2,3).

[modest ice]

Yall can u tell me which calculation is correct?

[weary arrow]

The one on the right is correct

Not sure why the one on the left got 10e-11

[modest ice]

Like yeh at first I thought they did sth with the decimals but they would only get positive above.....

[modest ice]

🥲aaaa thanksssss

[weary arrow]

probably just a casual error from going too fast, happens to everybody

Also we are currently working on the same thing lol I'm doing an exercise on parallel plate capacitators

[modest ice]

Owoah really hah all the best umm if u get stuck I can also try to help yooo

[weary arrow]

haha thanks mate, you too 🙂

[dusk harbor]

thank you

Does anyone know what is the mclaurin series for this?

[mint vector]

Can someone help me . How to solve n

[supple island]

i mean calculating the derivative is pretty easy

[dusk harbor]

yes but the sum i got is bigger than the function so i think i did something wrong

[supple island]

of course it's bigger than the function

no problem with that

[dusk harbor]

isnt it supposed to be near the fuction when n -> infinite?

[supple island]

it's supposed to approximate the function when x->0 and n->infinite

[dusk harbor]

ahhh

[supple island]

you just express the function with a polynome of x

so it's easier to graph

or to calculate the limit

[dusk harbor]

that include the point x=0 ? no right

[supple island]

McLaurin series is specifically for x=0

Generally Taylor series approximate in a neighbourhood of a certain point the function with a polynome of x

[dusk harbor]

this what i got for the mclaurin series

[supple island]

it's f(x0)+ that (where x0=0) and f(x0) is obviuosly 0

i'd write it to be more formal

then you'd also have to write (x-x0)^n

but it doesn't change much

it's just to be more precise

[dusk harbor]

ok ty for the help! im new to this taylor and mclaurin series im getting used to the concepts

[supple island]

dw can be a little confusing at the start

[supple island]

divide both the numerator and the denominator by pi^n

then you can simplify it and you remain with ((2/pi)^n +1)/((3/pi)^n -1)

but both 2 and 3 are<pi

so 2/pi and 3/pi are both<1

and what happens to a number<1 when it's elevated to a really big number?

[covert anchor]

21iii cant form the 2 equations required to do simultaneous

anyone that can help will be greatly thanked

[modest ice]

In the third one it says that the consumption of petrol is more when going up the slope than coming down and the difference between them is 5L ....so we naturally subtract the greater quantity with the lesser one i.e.
100/x - 100/(x+4) = 5

[native python]

hi could anyone help me with part C please?

[dusk harbor]

is this correct or did i do any mistake for mclaurin series?

[surreal hound]

you need to find an expression for the first toy car like x(t)

then do the same for the second

set them equal to each other and solve for t

be careful with the +/- signs. On is going in the +x direction and the other in the -x direction

for example, the equation of the second car could be: x(t)= 500 -1.2t

This is assuming it starts at x=500 and moves in the -x direction

[native python]

what is x in this case?

[surreal hound]

x = 500m

[native python]

so for the first toy car its 0?

[surreal hound]

right

one starts at +500m

the other starts at 0

[native python]

alright thanks

[real totem]

somebody help me pls

Olive has 600 fruit trees.
Some of the trees are apple trees.
The rest of the trees are pears trees and plum trees in the ratio 7:5.
There are 175 plum trees.
Work out what fraction of the trees are apple trees.

[weary arrow]

175 plum trees -> 7/5*175 = 245 pear trees. That means there are 600 - 175 - 245 = 180 apple trees. Can you find the fraction now?

[vale wyvern]

Anybody knows how to find

-1 ≤ [2x² - 3] < 2
x belongs to

[.] Is greatest integer function here

[real totem]

yeah I did that part already

but the fraction part is what I dont know how to do

[weary arrow]

ok, that's fine, just divide the amount of apple trees with the amount of trees total

[real totem]

thank you so much

sometimes I honestly think that I'm stupid

[weary arrow]

ehh, we all get stuck sometimes

[chrome cypress]

lmao

[latent siren]

This is really weird, do you guys feel melancholic and even a little anhedonic during the summer? I can't seem to work do meaningful work since yesterday.

[left knoll]

my math teacher is on x-games, bruh

[chrome cypress]

i mean not if u acc pay attention init

[chrome cypress]

i agree actually, happens to me but i jus do the work anyway

[rose otter]

haha a bit, I miss the disco

[dense cliff]

help w this one please?

[latent siren]

I don't know but it actually depresses me more when it's too sunny.

PS. O crap, I though I was in the general chat.

[chrome cypress]

(9*10^2n)^3/2 then simplify from there

[hollow escarp]

27 * 10^3n

[dense cliff]

okie thank u :)))

[dense cliff]

THANK U

now i know how to actually do it

[hollow escarp]

you shouldn't hesitate to ask if you have doubts. What's the point of all this if not ?

Glad to hear that btw. Good luck

[dense cliff]

thanks ;D

[minor scaffold]

Any folks studying probability here? Could use someone to bounce ideas off of for:

[minor scaffold]

Where I'm at approaching it numerically: https://nbviewer.jupyter.org/github/Per48edjes/Harvard-STAT110/blob/main/Problem 3.3%2C SP9.ipynb

Analytically, I only have a_1 which is expectation of a random variable ~ Geom(1/7) = 7 ... not sure how to use iterated expectation to get the recursion 🤔

[minor scaffold]

current thinking

[left knoll]

Hey guys
How would I work out tan 30/tan 60?

[minor scaffold]

here's a hint: express tan in terms of sin and cos and simplify

i'm also assuming here you're working in degrees rather than radians

[viscid thicket]

Guys, how do I know if a sequence converges or diverges? The way I understood it was, it converges if it approaches a limit, but Im confused on this question

I think it converges, but Im not sure, is it convergent?

[minor scaffold]

might be of use: https://www.khanacademy.org/math/ap-calculus-bc/bc-series-new/bc-10-1/v/identifying-sequence-convergence-divergence

[thick pine]

Assuming you want lim_{n to infty}

[minor scaffold]

whoa @thick pine , how did you render TeX in discord lol

[viscid thicket]

Damn, sorry but idk what that means. Im still in high school, taking a precalculus class. I just wanted to know if it was convergent or divergent?

[thick pine]

MathBot#7353

[thick pine]

If the bot is on the channel, you can use =tex \frac{1}{2} or some other command and he will render it. Otherwise PN him the code and copy paste the image here

[queen rover]

are we talking about the sum of a_n or about the value of a_n for n-> infinity ?

[queen rover]

cool

[viscid thicket]

Second one, the value of a_n for n-> infinity

[latent siren]

While boring, the definition of 'divergent' is simply 'not convergent'. Technically this means our sequence cannot be bounded arbitrarily as the terms increases. In more intuitive terms, no matter how far you get into the sequence, the terms do not settle into a specific value. However, there's quite a bit of subtlety to the notion, there are various ways that your sequence can diverge:

1. Your sequence diverges to infinity. Example: a_n = n, simply because as n approaches infinity, then so does a_n;
2. Your sequence oscillates indefinitely. Example: a_n=(-1)^n, this sequence will never settle to a specific value because its values just alternate between 1 and -1.

[queen rover]

then you take the ratio of the highest order terms

a_n for n = infinity is 3/2

also plug it in your calculator for n=100000 and check this is correct

[viscid thicket]

Does that mean it converges because it reaches a limit?

[queen rover]

it converges to 3/2

[latent siren]

Existence of a limit as n approaches infinity is the definition of a convergent sequence.

[queen rover]

an example of a diverging one would be if it said 3.n^3 instead of 3.n^2

because for large n, a_n would only get higher

[viscid thicket]

Ohhh ok, thank you so much

[queen rover]

np!

[minor scaffold]

yeah, you're 1000% right -- we need to add this bot to the channel

[left knoll]

Oh,I figured it out lol
Just left out a step

[minor scaffold]

omg 🤦‍♂️ this is coupon collector all over again y did this take me so long f lol

[left knoll]

Why do we equate the divisor equal to 0 or why do we find zero of the polynomial to find the value of variable in the remainder theorm and then substitute in the given polynomial in the place of varibale to find the remainder, in every question

[left knoll]

hello guys where could i learn the step function ?

[queen rover]

how do you mean?

its role in the laplace domain / a system's response to it? or are you talking about a signals course?

[cosmic pelican]

yo desperately need math help can someone pm me<3

super simple but im dumb

[queen rover]

dependin on what it is i can help for a bit

[covert anchor]

For 21

Should I use trigonometric ratios

[minor sluice]

guys what is better to take AP Calc AB or BC

BC you learn two more chapters but would yall say

[wraith zealot]

I would take AB before taking BC

[minor sluice]

We can skip AB and go to BC and I’m not going to take hard math senior year prolly

[wraith zealot]

Ohh ok well I'm not sure then. I took AB this year & haven't done BC so idrk the difference, just that BC is obviously more difficult

[left knoll]

can anyone tell how can i master calculus in a month

starting from today

[spring mesa]

i don't think bc is more difficult actually

ab is harder because you're learning all these new concepts

but bc is just building on those concepts

take ab first tho

[left knoll]

Can anyone who is good at math or understands this please tell me what it means or what it is at all please?

[left knoll]

Seems like schrodinger equations

Hamiltonian operatior and wave function?

i still dont understand

what is schrodinger problem

some dead azz cats

[marsh jay]

please at me but how the heck do you revise maths

[river oasis]

Hey there! Is anyone good at statistics? I need help. Does the size of the samples have to be the same for all samples for ANOVA? I need to analyze 3 groups but sizes are different: 40, 60, 80. Will it still be correct to count all the SST, SSB, SSW, and F, or do i have to use another method?

[queen rover]

You don't. You should study until it becomes a skill, not knowledge. Except if you are talking about learning formulas by heart, there's no way but to practice until 'it clicks' and it seems logical - as in you don't have to remember because you understand it.

hope it helps 🙂

[ashen laurel]

speaking the gospel 🙇‍♂️

[left knoll]

Hey! can someone help me?

[sterile vector]

I am getting it to be true for all real numbers except between -2/5 and 2, including end pts..

[left knoll]

answer is [-1,-2/5)

[sterile vector]

So I guess they have taken the under root quadratic to be greater than or equal to 0 for getting real solutions...i.e. -x^2+4x+5>=0

[river oasis]

my god, i guess i’m stupid as hell haha

[left knoll]

I'll try to understand lol

[river oasis]

no need if you have the correct answer already. my mistakes are only going to confuse you(:

[left knoll]

You've done a lot of places right

I think wrong section 1)...

Thanks a lot

[covert anchor]

What should I do for ij

ii

[hard jasper]

hey

I'm stuck with this one

does someone know how to do it?

[vale wyvern]

Someone know how to do it?
Its a multiple choice question

[vale wyvern]

Thanks but can I ask how you made the graph?
Means steps?

[covert anchor]

nvm

question 2 any ideas

[vale wyvern]

Sorry for the mistake in between😅

[celest quarry]

might have made a few mistakes but here

oh LOL nvm

[vale wyvern]

Can I ask which pen you use😅
Looks clean

Btw we both gave same answer at the same time:joy:

[celest quarry]

uniball signo RT 0.38!!! one of my favorite brands - it doesnt smudge and dries super quickly

[vale wyvern]

Cost?

[celest quarry]

im not sure of the currency but its cheap too - around the same cost of most pens you can find at stationary stores

[covert anchor]

one drop and unusable

[celest quarry]

oh really? ive dropped mine countless times and i still use it LOL

[vale wyvern]

I use $ 1/35 or $ 1/7 pens
Cheaper than that also?

[celest quarry]

im not sure what currency youre using haha ... its less than $1USD for mine

[covert anchor]

i dont understand the highlighted steps

[vale wyvern]

She has cutted the 1 line you highlighted

For the second line she bring the power of y which is ⁴ in. Front
And changed log x Y
To log x/log y

It is a property

[covert anchor]

And changed log x Y
To log x/log y

idu

[rugged imp]

sorry for the late answer. I was busy with something. With mod questions, the best approach is generally graphing it. Now to do it, first take some critical points. We also know that the modulus cruve is made up of straight lines. So we just need to join two critical points by a straight line. Here I chose the critical points as -3 and 3 and it should be fairly obvious why. Then I checked for x=0 because the generally is a good idea. This graph is a bit more intuition but, the other way is taking x range from -infinity to-3 then -3 to 0 then 0 to 3 and then 3 to infinity and making them by using the APPROPRIATE signs (very imp.)

[vale wyvern]

Prove of itand how it came...

[vale wyvern]

Ooooo👍 👍

Means I was going somewhat right
Lemme show you 1 pic

[rugged imp]

yeah that is an approach as well

But graphs are way faster

Because you get points and not lines

[vale wyvern]

I was very close to the answer but I got confused when it
Asked for lemda > 6

[rugged imp]

and you just have to join them

ahh

graphs are more visual

and they help more in these types of questions

[vale wyvern]

Yess😀

[rugged imp]

is this from alleen sheet by any chance

?

[vale wyvern]

Nope

Means you are an Indian

[rugged imp]

yep

youre indian too right

[vale wyvern]

Yep

[rugged imp]

I can tell by the handwriting

[vale wyvern]

Is it that bad?

[rugged imp]

it looks distinictly indian student

no

its good

this penchant for cleanliness in questions ccomes with time

you can tell after a while

[vale wyvern]

😁 👍

[rugged imp]

btw why do you have anbu kakashi as your dp

that was the most depressing one

[vale wyvern]

It reminds me of the hard work
Pressure and loyalty

[rugged imp]

oof

didnt expect an answer like that

goddamn boy you know how to talk

iill give you that

[covert anchor]

this is the step by step

but it doesnt need to be shown right

[vale wyvern]

Seriously?
I consider myself with bad conversations skills

[rugged imp]

because you dont try lmao

[vale wyvern]

Yep

[vale wyvern]

Ture

[rugged imp]

aight i have to get back to work

[vale wyvern]

Good luck!

[covert anchor]

is it a property

of log

[vale wyvern]

Yess

And you can take any base in log x/log y

[covert anchor]

got it

[vale wyvern]

I just left it

[covert anchor]

did not learn b4

[vale wyvern]

Great

[manic perch]

could I get some help? no idea how to do this lol

Here’s where I’m at

wait nvm i got it

that was wayy easier than i thought

[covert anchor]

hi how should i continue

my brain suddenly died

[serene ginkgo]

The question is for 9 find the coordinates of the 2 other vertices

[real totem]

In a sale, a shop reduces all its prices by 10%.
On the last day of the sale, the shop reduces the sale prices by 20%
On the last day of the sale, a mobile phone costs £432
How much was the mobile phone before the sale?

can smn help ?

[weary arrow]

does the question mean that the prices go down 10%, and then go another 20% of that, or do they go down 20% of the original price?

[real totem]

yes

apparently in the markscheme the answer says its 600

[left knoll]

Id say you just have to add 20% of his current price and then 10 %

[weary arrow]

ahh I see. Well what I would do is first divide 432 by 0.8, and then by 0.9

after the first sale the phone will cost 90% of original price, then after the second sale the phone costs 80% of the new price. So either go backwards (divide by 0.8 and then 0.9), or find what 80% of 90% is, and divide the price by that. You get 600 with both methods @real totem

hope that helps

[real totem]

I'll try that thank you so much

[steel plover]

anyone know what website I can use to find a graph of that func?

[quiet kestrel]

Desmos.com

[left knoll]

they have a graphing calculator ^

[slow cipher]

I don't get why P(X=x), what does little x and big X mean? (probability)

[weary arrow]

X = the thing you find the probability for x = how many of the thing

So P(X=2) is the probability of there being 2 of X iirc

[marsh jay]

so your saying continuously revise/study until the information is in my head naturally

[latent siren]

He's right. In a way math is similar to programming, it's a (hard) skill. You not only study it, but train yourself to be better at it.

[marsh jay]

ah.

[tardy bone]

Hey

Am i dumb or is there an error in my books explanation of the solution

Step 1 cant be right

Why would the exponent change?

[weak mortar]

1^{-1} is equal to what?

[tardy bone]

1

[weak mortar]

they skipped some steps

[tardy bone]

U sure this works?

[weak mortar]

they first divide by -2 in both sides and then they take both sides to the -1 the power

check for yourself thats the best

[tardy bone]

Ooooh

You can do that?

[weak mortar]

well its the same as saying 1/x = 1/y <=> x =y

the only condition is that a-1 is not zero

[tardy bone]

Ah okay

So this doesnt work if a =1

Even if the other side of the equation was zero?

[queen rover]

let me give an example. You can try to remember that functions like y = x^2-4 have a negative and positive solution or you can draw x^2-4 on a plot and see that it crosse the x axis 2 times. Once you see that, you don't have to 'accept' that there are 2 solutions ( with the danger that you might forget). You will understand why it has 2 solutions and it will be harder to forget too. And the same goes for a million other things in math.

[marsh jay]

ah ty

[formal prism]

anyone know the answer to this? so confsued

[latent siren]

I'm a little busy so I'm just going to give you a hint:

@formal prism

[formal prism]

ohh shi ill try that

[latent siren]

The formula that I gave in c) is from the chain rule

[formal prism]

okay i got a and b that was easy

let me try c

[latent siren]

You should also figure out why is the a_12-th entry given by such a formula!

Oops, there's an error in a)

[formal prism]

wait how

[formal prism]

oh yea

thats what i did

[latent siren]

the 2nd coordinate of f is v, you should compute a_12 by partial derivative of v

[light widget]

hello, sorry for disturbiing.. im studying calculus right now, and i really need help, i can't get the correct answer for one question.. can someone help me?

[formal prism]

im so confused how to do part c though

like

idk ima skip that one

[latent siren]

You're kinda one-thirds done with c if you know a and b.

The a_{12} entry of (Df)(0,1) is just the a_{12} component of Df evaluated at u=0, v=1.

[formal prism]

hm okay

hold on i skipped it lemme finish this assignment and ill go back

thanks for the help!

[queen rover]

it should be pretty straight forward but i'll write it out for you

[light widget]

i got -2(x^-2 - y^-2) for left side *idk if it is wrong answer or what,.. but i so confuse to get the real answer for the right side..

[queen rover]

okay. so here it is. To be honest it required some pretty strange steps for putting the z back in.

Hope you can read it haha

[light widget]

i try to read it first ;)

[queen rover]

Make sure you have the derivatives correct first 🙂

[light widget]

thank you so much!! you are so smarttt and geniuss 🤩 🤩 i understand what you wrote ! THANK YOUU @queen rover !!

[queen rover]

Happy i could help! Good luck with the rest of your studies 🙂

[woeful shore]

hello guys

i need a bit of help

if someone can dm me how to do this

that would help a lot ty

the question is :

**Two non-zero vectors , a and b are such that **

|a+b| = |a| + |b|

Explain geometrically , the significance of this statement

(1 mark)

[supple island]

ok so this means that the module of the sum = the sum of the modules, when you do the sum of two vectors you don't just sum their lenghts(their modules), right? but there's one specific case where you do

[woeful shore]

hmm maybe , but i am not sure if u need to make calculations as it is only 1 mark , so i am stuck as i just dont really understand what i need to do here

[supple island]

let's put it in another way

[supple island]

graphically how do you represent the sum of two vecotrs?

[woeful shore]

well , to represent it graphically , u would start by drawing the vectors from the origin (O) to their (i , j) coordinate and connect them using the head-to-tail method

i think

that is how i would do it

like this , right ?

ofc AB would be -OA + OB

[supple island]

oh ok

the sum is with parallelogram thing

[woeful shore]

ye , the hypotenuse

[supple island]

more like a diagonal

but yeah my point is, can you imagine 2 vectors, the sum of which is a vector that is just the 2 vectors attached together?

[woeful shore]

but with magnitude , | A | u would

[woeful shore]

i am not sure what u mean ?

[supple island]

what does this have to do with the sum of 2 vectors?

[woeful shore]

i was just showing u what the mag would be , like in the question

like what it is

[supple island]

yeah i know what that is, not i'm asking you right now thou

this is what i'm talking about

are you familiar with this?

[woeful shore]

yeah

in terms of how to draw one

[supple island]

ok good, now try to imagine to bring closer and closer the 2 vectors

when you bring them so close that they actually touch, what happens to their sum?

[woeful shore]

so like this ?

the 2 vectors touching each other

[supple island]

uuuuh

no i mean bring u and v close to each other

reuce the angle between them

[woeful shore]

oh 😅

amm

i dont know honestly

[supple island]

ok so try to imagine a parallelogram but you reduce the pair of acute angles

the whole parallelogram becomes longer right?

[woeful shore]

so the u+v in this case , right ?

idk what u mean , sorry , cant imagine that

not smart enough 😅

[supple island]

ok?

[woeful shore]

yeah okey

[supple island]

no we stretch the parallelogram even further

so much that AD and AB actually touch each other

[woeful shore]

to get a straight line from a to c ?

[supple island]

if we want to calculate AC

yes

AC is just the sum of AD+AB, right?

[woeful shore]

ye

[supple island]

so you could say that the lenght of AC is equal to the sum of the lenghts of AB and AD

[woeful shore]

yes

[supple island]

now imagine that AB and AD are yor vectors

AC is their sum

[supple island]

and remember that for vectors lenght=module

[woeful shore]

okey , what would be the form we write it in ?

[supple island]

well your vectors are now in a certain condition

are they perpendicular, parallel, do they have to face a specific direction?

[woeful shore]

i mean ,its not given that info in the question

so i assume no

in terms of direction

[supple island]

well that's what you have to say

[woeful shore]

?

[supple island]

the question gives you a property

you gotta say with which conditions this property is met

in what conditions do you think these 2 vectors are?

hint: they stay on the same line

[woeful shore]

so

all i have to say is that a and b lie in on the same line in the same direction ?

as these are the conditions the vectors are in

[supple island]

that's called being parallel

so if |a+b|=|a|+|b|, a and b are parallel

[woeful shore]

oh , thank you for explaining the question

thank you

[supple island]

np

[gusty vault]

??

[tawdry hazel]

The rest is substitution; if you need help with that let me know

[covert anchor]

for question 5

I intend not to change the left hand side since it is already the term that we want to get the value of

but can't seem to carry on , hoping someone would guide me

[tawdry hazel]

its better to simplify every term to 3^a

[covert anchor]

gotvha

[tawdry hazel]

let me know if you need more help with it

[covert anchor]

why to the power a thogh

[tawdry hazel]

oh by "a" i meant any number

[covert anchor]

noted , trying out again

[tawdry hazel]

kk

[covert anchor]

Currently doing deep revision many questions im not sure how to do

[daring oar]

any help please?

[left knoll]

hhhhhhh

[candid mauve]

The supplier reports this year, 30% of all potatoes have blemishes. A bag of potatoes sold by the supermarket contains 52 potatoes.

Calculate the probability that in that bad of 52, more than 8 but not more than 31 have blemishes.

is the answer this or not : 22/52 = 0.423 or 42.3%

[exotic dust]

lkmao what the fucl ois is wrong with my microphone like i feel like i am susshc a a csususys baka you onw aht i mam sayong=

[left knoll]

mattaku

[covert anchor]

Hi what should i have done

I have done these so far

[gusty vault]

??

[left knoll]

5u - 4/u = 8
5u^2 - 4 = 8u
5u^2 - 8u - 4 = 0
And its solving the quadratic from there

[covert anchor]

ok

i have gotten 2 and -2/5

and idk what to do ne

[mental snow]

ok so u get

5u^2 + 8u - 4 = 0

u = 2/5 or -2/5

so e^2x = 2/5

2x = ln(2/5)
x = 1/2 ln(2/5)

[covert anchor]

what

[autumn sorrel]

2?

[steel plover]

as in the face of the prism

[left knoll]

Can someone help me?

[queen rover]

If you consider y a variable you can recognize a quadratic equation in y (just consider x a number for now). Write out the expression for y according to that formula. You will see that y will not always be real but can be imaginary. Think what x values will make y imaginary considering the square root part of the formula 😉

[left knoll]

Okay i'll try

Ty

[queen rover]

if you can't see it, just ping me i can write it out too

[covert anchor]

i have gotten ii and i

but cant get iii

[queen rover]

I think this is mainly about expressing the clue mathematically

@covert anchor

[covert anchor]

same

but thats not the ans

its crazy

ans is 6600

[supple island]

with that k answer checks out just fine

i don't see the problem

you got A(t)=4.5=10e^(-kt) where k is known

so you have ln(0.45)=-kt -> t=-ln(0.45)/k

it's 6600

[left knoll]

I didn't see,can u do it? @queen rover

[queen rover]

If you can’t read something, feel free to ask

@covert anchor if k is equal to the value i gave, question four gives you 6600 years

[left knoll]

TYSM <3

[gusty vault]

Can someone help with this integral ??

[scenic remnant]

i need to confirm my answer, for me it is x= 1, y=-5, z=-5

[humble osprey]

sorry

[gaunt rock]

thats pretty simple.

[scenic remnant]

that's the method i used yes

[gaunt rock]

but whats the problem?

[weary arrow]

your answer fits the equations

[scenic remnant]

i don't have the answer to it so, i was a bit anxious if its right or wrong

[scenic remnant]

...sorry...i have lost braincells...thank you...

[weary arrow]

it's fine! it's nice to double check sometimes

[gaunt rock]

just substitute it in to see if it works.
1 -10+15=6
3+-10+10=3
2+5-5=2

it's correct

[scenic remnant]

thank you so much, @gaunt rock @weary arrow : D

[left knoll]

@scenic remnant you from?

[subtle parcel]

Anyone who has studies Analysis

[candid mauve]

The supplier reports this year, 30% of all potatoes have blemishes. A bag of potatoes sold by the supermarket contains 52 potatoes.

Calculate the probability that in that bad of 52, more than 8 but not more than 31 have blemishes.

is the answer this or not : 22/52 = 0.423 or 42.3%

[scenic remnant]

India

[left knoll]

oh! Neighbour

[scenic remnant]

[queen rover]

how did you come to this conclusion. Which distribution did you use and between which bounds did you integrate?

[candid mauve]

well the probility formula is:

p= how many time a specific event can occur/ total events

So,
The possibility of events where having blemish potatoes is in between 8 and 31. that will be 22. The total amount is 52.
Thus,
P = 22/52 = 0.423

[queen rover]

oh i'm afraid it's not that simple my guy

the probability for every potato to have blemishes is 0.3. Basically you're doing the experiment of taking a potato and looking if it has blemishes or not 52 times and when you're done you add them up.

doing this single experiment is called a bernoulli-experiment, doing seeveral after one another is a binomial distribution.

the binomial distributions is a function of the number of trials (n) and the probability of a single event to occur (p), then there is x (the function's variable)

You're trying to calculate P = Bn(8<x<=31 | n=52, p=0.3). Bn stands for binomial distribution and you fill in your bounds (8 and 31) and also n and p.

you can also write P as P = Bn(x<=31 | n=52, p = 0.3) - P(x<=8 | n=52, p = 0.3)

and you'll have to use tables or an online calculator to get the numerical values

[candid mauve]

oh alright I got. thank you man. I was really lost.

❤️

[queen rover]

np. here's a short video if you need some more info on the binomial distribution https://www.youtube.com/watch?v=3EZbX2ftCUk

[maiden sigil]

I dont understand direct varation

[left knoll]

when x increases,y increases. Or, when y decreases, x decreases.
y = kx
k = 1/2

[maiden sigil]

oh ok

[maiden sigil]

@left knoll I got y=10 for the answer can you confirm

[vale wyvern]

Google forms
Means ur test going on

Well the answer..

We can see as y=3 x=6
Therfore
y = x/2
as y it directly varies with x
Now,
y = x/2 = 20/2 = 10

y = 10

[maiden sigil]

oh so I did get it right thanks for the confirmation @vale wyvern

[viscid thicket]

Guys, do limits exist at holes?

I have this graph

And I have to get this

And I got
a) 2
b) 2
c) Idk
d) DNE
e) DNE

I dont know if c) would be DNE because there is a hole or 2 because both sides approach that value

[mental wraith]

a) 2
b) 2
c) 2
d) DNE
e) DNE

[thick pine]

c exists because lim+ = lim-, but the function is not continuous in -1

[glad grove]

Does anyone know how to use Mathematica? pm

[left knoll]

Help pls

[viscid iron]

Is it difficult

[vale wyvern]

You want to simplify this expression?

[viscid iron]

No but I can simplify it if you want

[craggy plume]

Tips for add math? I keep forgetting which method and stuff do i use to solve the question when the exam comes

[vale wyvern]

By my experience
I think you are not understanding it, why it is happening and what it does?
Its more like seeing learning and learning steps again and again

If you wanna learn maths (my way)
Just ask why is it happening? And what it does?
You will remember it that you have to do to get this and then we can get this
Then we can get the answer.....

I never learn derived formula
For example I solve projectile questions without formula...its easy for me...

[covert anchor]

hi can anyone help me ?

i need to find x

[karmic grotto]

@covert anchor Start by multiplying out the denominators. So multiply the left and right side by x*(x+4) and you can get things to cancel out so that you don't have to deal with the denominators anymore. You can dm me if you still get stuck.

[steel plover]

can someone explain how he got cos pi/3 from 1/2 and sin pi/3 from sqrt3/2

[karmic grotto]

@steel plover From the unit circle, cos pi/3 = 1/2 and sin pi/3 = sqrt3/2. Sort of reverse engineering it from the way most people were taught.

Then the part after that comes from this identity

[steel plover]

ohh I see. couldn't wrap my head around that one at first

thanks!

[left knoll]

@covert anchor did you solve the problem?

[mental snow]

do we need to simplify this expression?

[misty sun]

Does anyone know anything regarding vectors? I really need help with this assignment, I'm clueless

[supple island]

this is very basic, i suggest to just read your text book

because these exercises require nothing but knowing what a vector is and how to represent it

[left knoll]

A microscope is focused on the upper surface of a glass plate. A second plate is then placed over the first. To focus on the bottom surface of the second plate, the microscope must be raised 0.780 mm. To focus on the upper surface, it must be raised another 2.10 mm. Find the index of refraction of the second plate.

can some one explain me this question and how to solve it?

[analog wagon]

Let the determinant of 3 cross 3matrix A be 2 n B is a matrix defined by B=5A^2 then det(B) is..I'm getting 20 but gvn ans is 500.. anyone?

[queen rover]

500 is right. let me write it down for you

[mental snow]

alright so when a scalar is multiplied with a determinant it gets multiplied with each row / column of the determinant

so since its a 3x3 matrix

5 will come out of each of them first

so

5^3 x 2^2
125 x 4 = 500

|5A| = 5^n |A|
where A is an nxn matrix

[queen rover]

^this is right. Here you got the proof too.

[modest ice]

Bruhh can somebody tell me which one is wrong and what was the mistake🗿

[light heart]

Guuuys please help me

i need to calculate Ct pls how do i get Ct out of the fraction?

[fallen dock]

Ct× tA/2= 0,7v....

Ct=0,7v...÷tA/2

Does that make sense?

[light heart]

i think that's what i did but i am not sure

Thank youuuuu so much

[light heart]

i find that logic yes

[fallen dock]

No problem!

[modest ice]

So like in the end is 10^4 the answer corona the rhs u cut the 10 on the down but didn’t write it ummm or am I

[covert anchor]

yes

sorry for the lte reply

[left knoll]

No problem

[covert anchor]

Anyone able to guide me

I just need this question

[upbeat basalt]

If the number of bacteria doubles every 5 hours you just can choose a fitting N₀ and double it to get your N. t would then be 5. Then you just need to solve for k
If your N₀ is 5, N would be 10 for example

[covert anchor]

why is it double ?

[upbeat basalt]

because the task says so. For every 5 hours the number of bacteria doubles

[covert anchor]

ok

in his working why did he write e^k.t ?

[upbeat basalt]

With this information you can derive what naplandau sent

[upbeat spire]

thats the expression for exponential growth

right ?

[upbeat basalt]

The dot is kinda misplaced. Its a multiplication sign

[covert anchor]

ok got it thanks

[covert anchor]

yep ik

thks all happy learning !!

[analog wagon]

thank u very much

[analog wagon]

thank u!

[analog wagon]

If A is a matrix of order 3*3 n |A| = 2 then determinant of co factor matrix of A is ?

anyone?

[left knoll]

Is 4 a ligma number

[ivory pumice]

4

[ivory pumice]

^^

AAc = |A|^n [I]
Taking determinant both sides and solving , |Ac| = |A|^(n-1)

[analog wagon]

is this result valid for both adjoint n cofactor?(though there is a minor difference) btw Thnx!

[minor scaffold]

General Q: how do folks use Anki for maths? Seems like doing problems/thinking deeply helps, but do people "memorize" proofs or theorems or the like?

[latent siren]

What I did was to 'physically' practice some proofs, i.e. I kept proving the same thing, over and over, by writing, if I can.

For exams, I think some memorization does help.

[wanton shadow]

a physik question not sure were to ask for

The question is asked in germen ima try and translate it in english

A ball starts rolling whit v = 20 kilometer/ hour on a hill that has an angel of 32 degree
there is a friction coefficient of 0.016

we are looking for when does the ball stop rolling time and after how many meters

if been trying it but nothing even comes close to the answer so id be realy thankful for any help

[supple island]

where is the ball going? uphill or downhill?

[left knoll]

Hey y'all. Anyone know calculus on here? How do I find the parametric equations and how do I graph them?

[mental snow]

-x/4 = cos t
y / 4 = sin t

Using sin^2 t + cos ^2 t = 1

X^2/16 + Y^2/16 = 1

X^2 + Y^2 = 16
Eqn of a circle with radius 4 and center at (0,0)

[mossy fjord]

What is the answer?

[wanton shadow]

it would be uphill and the answer is 2.89 meters

[supple island]

ok so this problem requires doing energy conservation, do you know how to do that?

[wanton shadow]

not realy more liek first time hearing it

[supple island]

are you not familiar with mechanical energy?

[prisma laurel]

Can someone guide me on how to get started with Variational Calculus?

Which topics do I need have prior knowledge of?

[wanton shadow]

we had it very simple till now

[wanton shadow]

2.89 meters

[supple island]

ok, so if i'd ask you what kinetic energy is what would you say?

[west valve]

Can someone explain the remainder and factor theorum to me pls

[vagrant depot]

i have a maths book and i want to complete it asap how do i start understanding stuff as i currently dont have a tutor

pls dm

[mossy fjord]

U have velocity given (intial is 20km/hr, final is 0) and acceleration can be found out by this formula
(The photo)

Acceleration will be 5.326 nd using v^2-u^2=2as
S will be 2.897 m

[analog wagon]

Covalent solids have covalent bond and ionic solids have ionic bond, right? And ionic bonds are usually stronger than covalent bonds, so why covalent solids are harder and stronger than ionic solids?

[analog wagon]

Ahh sry posted in the wrong section

[wanton shadow]

thank you 💙

[compact talon]

No probs

[wet sparrow]

Hi guys

Can anyone help me solve this one? It's a practical example suggestion from my book

It does not have the sol though

[mental snow]

Hello, I am getting

(5-16 root3) / 5

[wet sparrow]

I got -16root3/5 + 1 here

It's written in my mother language

[mental snow]

yeah

[mental snow]

ohh ok

[mental snow]

i got the same 😄

[wet sparrow]

Thank you so much!

[mental snow]

😇 cheers mate!

[wet sparrow]

my scanner is so bad sorry 😦

[mental snow]

yeah i can figure that out

[wet sparrow]

@mental snow can you give me a hand on this one?

[mental snow]

sure lemme try

[vapid isle]

How do we learn inverse trigonometric functions?

I dont know how to learn the graphs , range and domain

Can someone suggest me a good website or book to refer to

[mental snow]

oh my god i am getting a very weird answer

[wet sparrow]

what kind? xdd

the first or second one?

[mental snow]

f(3/5)

is

(5 root 3 - 4 - 2root3 ln3) / 5

i might try it again

whats urs ?

[wet sparrow]

i got \sqrtr3 - 2/5\sqrt3ln3

[mental snow]

ok lemme try one more time

theres an extra 4/5 i am getting

@wet sparrow

[mental snow]

i tried again and got the same answer

the extra -4/5 was from
2/5 root (5x-2) x (ln (5x-2) - 2)
when u put x = 3/5

its -4/5

[wet sparrow]

ohhhh

can you show me how you did it?

[mental snow]

so
[5root3 - 4 - 2root3 ln3] / 5

ok

@wet sparrow

[wet sparrow]

ohhhh

now it makes sense

thanks a lot man!

[mental snow]

U can further get c then

[mental snow]

Ohh

[mental snow]

Yayyyy

[covert anchor]

Hi what does this even mean ?

[mental snow]

Ok so as you change p, the lines slope keeps changing

At some p, the line won't touch or intersect the curve

So you can put

Y= px -2 in the curves equation

You ll get a quadratic

Now since the line is supposed to not meet the curve

There must be no real roots of that quadratic

So make the discriminant of that quadratic as negative

[covert anchor]

oh

wait where is the discriminant again\

[sharp ferry]

Heyo I had a super silly doubt

So in this one I just want to know how do we add a scalar to a matrix do we write 2 as 2 times the identity matrix?

[pine kelp]

You can't add a scalar to a matrix. You can add two matrices.

[sharp ferry]

I know exactly but how do I prove this then

Coz the terms except 2 is a matrix

And i calculated it and I got -2*I

So the only way this can be zero is if the other term was 2I instead of just 2

[pine kelp]

If it's pure mathematics, then I think the question is probably incorrect. However in computer science, there are workarounds.

[mental snow]

you can multiply identity matrix to the scalars to make the whole equation in terms of matrices

[mental snow]

yep

[covert anchor]

wghat do i do

i have found

p<31.74901573

[glad sierra]

I know this is something super silly that i've forgotten
but if anyone can explain how the summation i've circled leads to 4 in the next step do let me know! thanks in advance ❤️

@marsh kettle if you're there

found it ❤️

if anyone is curious 🙂

[covert anchor]

or should i just use quadratic formula

[covert anchor]

isnt x supposed to be greater than 4

[ruby tinsel]

Hi guys, I am trying to differentiate this function here. Could someone please help me? It is ln [x^2 sin(x)] cheers!

[static steppe]

VI-ET NAM

[polar heron]

Apply both product rule and chain rule.
y' = dy/dx= 3 *[ ( cos(x) * ln (x^2 sin(x))) + (1/(x^2 sin(x) ) ( 2 x sin(x) + x^2 cos(x) ) ].

[ruby tinsel]

Thank u,, this is the answer I got I’m not sure if I am right

[polar heron]

seems correct to me.

[ruby tinsel]

Awesome! Thank you!

[marsh kettle]

Sorry bro I was out

[opal canopy]

Does anyone 7th grade maths

[queen rover]

well i have done it 🙂

[lilac granite]

Someone can help me to solve this question?

[covert anchor]

Am I doing it right ?

[north jay]

i dont think so but im also not entirely sure

cause you grouped up a with b

i did it a different way and got exactly what you have

so now idk

are there answers?

[covert anchor]

no answers given

[north jay]

hm fuck

[covert anchor]

but i would like to see your method !!

for me

[north jay]

it turned out to be the exact same thing you did lol

[covert anchor]

i grouped them so i could =0

[north jay]

i just read yours wrong

[covert anchor]

is your method similar ?

[north jay]

yeah

basically same thing

you found k right?

[covert anchor]

yes

21.58

or 0.416

[north jay]

then i guess that must be it

sorry i couldnt help you more :/

are you in high school?

[covert anchor]

hmm we dont call that in my country

but im arnd 14

so i guess

[obtuse gate]

(-k-3)^2 = k^2 + 6k + 9, not -6k

your final quadratic should be k^2 -10k +9=0 which factorises nicely.

[tribal sable]

seems easy but idk why i couldnt do it could you helpp

[glad sierra]

no worries bruv

[weak mortar]

so the shortest route is through Be town so you could place A, B and C on one line. In the first case we see that the distance to A is 3 km and B is one km so we conclude that the distance between A and B is 4 km we so suppose know on the second board we know that A is 6 km to the right we now that B is 6-4 km to the right

[queen rover]

Just drew it out :p couldn’t not share it at this point haha

[left knoll]

help please

[left knoll]

Can anyone help me with this?

[modest compass]

You can use similar triangles i think

[supple island]

AM=3/2MB SO AB=AM+MB=3/2MB+MB=5/2MB, CB is given by CB=AB*tan(30)

[supple island]

how are they similar

[supple island]

now that you know CB and MB it's quite easy to find theta

[modest compass]

Same height

@supple island

[supple island]

the fact that they have the same height doesn't make them similar

your solution is the actual proof that they aren't similar, because with theta being 55° there's no way they are similar

@modest compass

[dense geode]

I do think that you get the same answer

[modest compass]

Yeah i just realised that actually 😅

Thanks for correcting me

[supple island]

np, thanks for being reasonable

[left knoll]

Thank you guys so much for helping me✨✨🙏🏻🙏🏻🙏🏻

[cobalt rapids]

can someone explain the right answer please ty

[queen rover]

i am not sure what the notation of the 'first' part of g(x) means. If you can tell me what they mean by minimum{(t): 0<t<x} i could help you further.

@cobalt rapids

[cobalt rapids]

i think its a typo

it should be min f(t)

[supple island]

what's the minimum value that cosx assumes in [0,pi]?

[eager falcon]

pi/2

[supple island]

no

[supple island]

also i'm not asking which x gives the minimum value, but even if i was the answer would still be incorrect

[eager falcon]

what do you mean

the least cos x can be is -1 is thats what your talking about

[supple island]

yeah cos(pi/2) is not -1

[eager falcon]

ik

[supple island]

ok so why did you answer pi/2

[eager falcon]

mistakes happen

[gentle tangle]

can someone help me?

[queen rover]

I bet someone could 👀

[gentle tangle]

help pls guys

[queen rover]

joking. give me a sec haha

but maybe ask a specific question?

[gentle tangle]

ok

no, i just can't ask this question

[hoary vine]

does by any chance anyone here knows how to calculate de Gini coef. with integrals ?

[queen rover]

@gentle tangle do you not understand what their questions mean or aren't you able to calculate?

you see, i could just give the answer but it's better if i help you find

[gentle tangle]

i don't know how to calculate

and the questions are confusing

[queen rover]

so i assume you know what the domain is?

(what it means)

[gentle tangle]

domains

i'm thinking how to say this in english

[queen rover]

well it's okay

so the domain is the range of x values between which the function is defined

what would that be here?

[gentle tangle]

hm wait

i don't know if I'm sure, but in line with X there are numbers, are they pauses?

[queen rover]

no. so the function is defined for all points between just two x-values

[gentle tangle]

[queen rover]

okay i guess you're having a hard time

[gentle tangle]

;/

[queen rover]

so you see how if you look at the x axis, the orange line is drawn for all numbers between a certain beginning and end? for example: for x=2 you can see how much y is ut for x = 8 ther is no information given?

you will see that if x is in between 2 numbers you will always be able to look what y value it has but for x values that are not between those two numbers, you won't know what y value it has

[gentle tangle]

ok i think

[queen rover]

have a try at finding what numbers mark the end and beginning of the function

[gentle tangle]

4 and 6 or -2 and -6 idk, is this?

[queen rover]

the answer should be -6 and 6

because for all values of x which are above -6 but below +6 you will see there is an orange line above it

[gentle tangle]

oh yes i can see

[queen rover]

so essentially you look at wher the orange line stops and look down for which x value that is and you do the same for the beginning

[gentle tangle]

ok

[queen rover]

so you might be thought to write your answer like this: Dom( y(x) ) = x element of [-6;6]

now for b: do the same but look for which y values the orange line begins and ends

[gentle tangle]

ok wait

[queen rover]

that's the meaning of image of a function: all the y-values for which there exists (at least one) corresponding x-value

[gentle tangle]

in the Y is 4 and -2?

[gentle tangle]

hm what?

[queen rover]

so instead of looking on the x axis, you look on the y axis

[supple island]

@gentle tangle i highly suggest rereading your textbook or watch some videos, these concepts aren't easy to explain by chat

mostly because a visual representation helps a lot

[gentle tangle]

@queen rover would you mind talking in dm?

[queen rover]

that's okay

[gentle tangle]

ooh ok i apologize for anything

[supple island]

you don't have to apologize, but i think you'll have a better understanding of the concepts with a visual representation that a chat can't give

[gentle tangle]

i'm triyng

[supple island]

also note that these concepts are much easier than they seem

[left knoll]

Hi guys,how do I factor this using difference of 2 squares and the difference of 2 cubes? I don’t quite understand the working out

[balmy drift]

@timber galleon will help

[timber galleon]

(x^3 - 8)(x^3 +8)

using this

(x-2)(x^2+4+2x) * (x+2)(x^2+4-2x)

using this

[balmy drift]

@left knoll

[timber galleon]

ezzzzzzzzzzz

[left knoll]

I go that but my tb memo says = (x-2)(x^2+2x+4)(x+2)(x^2-2x+4) unless this is just a complicated version of the answer that I’m not paying attention to lol -

[timber galleon]

its the same?

[left knoll]

Oh is it ?🤣

[timber galleon]

in yours it says 2x+4 in mine it says 4+2x

[left knoll]

Oh lmao sorry LOL

icic

Thanks

[balmy drift]

u can instal "photomath" @left knoll its Croatian app for math