#math-help
1 messages · Page 34 of 1
no
h is intersection between ac and mn
guys
is anyone there
indian grinder how should i use ∠AHM = ∠BGN
mahn is this hard or only i am finding it hard?
its grade 8
lolllllll
Its not
I just entered the server and saw this problem floating here
@cyan night Have you learnt euclidean geometry?
Its needed for this problem
Apparently i haven't
what is that
i dont think so and it doesnt need it
It does
my teacher made it possible for grade 8 knowledge
@median turtle hey is the figure correct?
that's only under the assumption that he's saying the truth
Nope
Ok let me explain
😦
It may take some time, but it should be the solution
okay
basically
what you gonna do is
make a random quadrilateral
let me fix one up quick
ok
what are those labels lol
ok
so its kinda bad
ok
If you see the drawing closely
You realize that by dividing the quadrilateral by AC
You get 2 triangles
so if you can prove that those are congruent
you can say that AC = BD
yeah
since ∠AHM = ∠BGN is given
so
try it yourself first, proving the congruency of ABC and ADC
actually no, its ACB and BDC
wait so doesnt that mean g is the midpoint of bd?
oh nvm i thought g,h,n are alligned
these have nothing but dc common
what
now draw it and prove its congruency using SSS rule
no i am figuring out in a different direction
ok
I'm at work. Rely on others for now ^^
ok
im self relying
wait @median turtle are we considering that ac = bd or ahm = bgn
both are given
use both of them
It's thales
yeah
Yes too easy
Yes
yeah so basically what i did was i drew the midline of trapezium abcd
the midline connects the midpoints of ac and bd so its also the intersection of the diagonals of the two parallelograms
Medline of triangle
Qf right
yeah if thats how u named the midline of trapeziu
qf = 3+5)/2 = 4
qf is also the midline of triangle mnk
qf = 1/2NK => NK = 8
Yes
@cyan night
help
Find all possible cases of x y and z such that the equation
algebra
Yes help
i remember already doing it
but i dont remember how i did it
bruh
because i never concentrated in my algebra class
@left knoll
any idea?
The question is: find all cases of x y and z such that the equation
nevermind
u stillneed help?
yes?
just algebaically simplify
i solved it
Ok
i neatly solved it
Ok
do u want to know the solution or do u know how to do it
Nah I did it
👍
(x²+y²+z²)²= x⁴+y⁴+z⁴+2(x²y²+y²z²+x²z²)
Yea I figured it out thanks tho
can you please translate this?
I need to sole this
hey someone break mid term in 3x^2 - 4√3x + 4
It is a perfect square@short rover
(√3x -2 )²
3x²-2√3x -2√3x+4
√3x(√3x-2)- 2(√3x-2)
(√3x-2)²
Still need help? If yes then I will do it after 1hr
Yes ok no problem I what to see the right answer
(a) you can't conclude anything about sum(a_n) because, as a_n > b_n for all n, all you know is that sum(a_n) > sum(b_n) for all n, which tells you little about whether sum(a_n) goes to infinity or not when n is very big. Therefore, there is no way to know if sum(a_n) ever converges or not, it all depends on the expression for a_n
(b) You know that 0 < a_n < b_n for all n. Therefore, 0 < sum(a_n) < sum(b_n). As sum(b_n) converges to a real number, that means the value sum(a_n) is contained between two real numbers, and thus cannot go to infinity (diverge) when n grows infinitely large
That's called the comparison theorem
Your second-to-last line is wrong, it should be :
= (2x - 3) * (x + 3)
That's because, from the previous line, you factor out (x + 3)
@left knoll
The last line is just the final, factorized expression for f(x), with all the factors you found : (x-2), (2x-3) and (x+3)
Ah ty so much bruhh 
How did I do it :- assumed t = 3x+2y , 3+y' = t` , y' = t/t+2 , and then solved it
5x⁶/y⁴= -9x⁵+89
How did I do it , assume t= 1/y³, divided the whole equation by y⁴ , t= 1/y³, dt/dx = -3/y⁴ dy/dx , substituted this and then used leibneiz form method
Hello Im currently in middle school and would like to learn algebra 1, 2 and 3 online.
Does anyone here knows any good sites?
The links in #useful-links might (and i think they WILL) help you.Take a look.
There are amazing websites that are suitable for learning math, physics etc. like KhanAcademy and Openstax.I recommend them @tawny ingot
Can someone help me with this? Its Simplifying Complex Fractions
This is what I have so far not sure if its correct though
you are correct!
for these problems, just simplify them into a common denominator in both fractions and u can solve it
Thank you!
Thank you so much
You're welcome 👍
Given right triangle ABC (AB<AC). On the collinear ray with ray AB, take point D such that BD = AC. On the collinear ray with ray CA, take E such that CE = AD. DC intersects BE at F. Prove that ∠CFB = 45◦
can someone help me out with a?
B part
Y u took the exponential function ????? Means in second step
We can also use u / v formula Sloving sinhx and cos hx
Yes we can..but I have solved many questions by taking exponential functions so that's why
Can u explain because , I didn't understood !
I have just started doing derivatives .
thanks!
Glad to help !
anyone knows how to solve this?
hyperbolicfunctions.pdf
@zenith quarry
This might help u ,if u r learning derivatives
just a sec
oh this is an exam
i cant help you with an answer
use the identity
i think a - is like the elements in the universal set which are not in a but im not sure
multiply by y , find the roots of the polynomial then inject in the relationship : y^3-y^(-3)=...
hes in an exam, its against the rules
hello, i have a problem. I need to calculate the area of a triangle, but I only have this available: a=12cm,α=35 and β=75. I get 113.943 cm^2 but the answers say it's 135.1, can anyone help? bcs idk if the answer in the book is mistaken or if my answer is not correct. Thank you!
If possible can you send pic of the diagram
Try calculating value of sides using angles and then use Herons formula
Bro I think the angles ąlpha and Beta are the ones on each end of the line a
BC= 12cos (beta) and AC= 12 cos(beta) cos (alpha) but those values turn out to be so small that triangles property is violated
So, i guess we need to find suitable triangle and then calculate area
ohh i see it now, I actually also turned around the angles
lol
I'll try again lol Thank you!
Guys can someone from India who studies engineering or medicine please dm me
can someone help me guess what this function is
the value on the y axis that's blurred out is 3
y = -1,5x +3, thank me later
Nah seriously, that graph looks strange to me. Maybe we could start by make a list of the info we have :
- tends to 0 when x tends to inf
- global min and max
- f'(2) = -2 (because tangeant to y = -1,5x+3 at x = 2)
- positive with 0 < x < 2
- negative with 2 < x
- roots at x = 0 and 2
Additional (not rigourous) info :
- global min seems to be at x = pi
- only accepts x >= 0, it might indicates a sqrt or log
Does anyone know how can I turn this
into this?
Im stuck :c
I need the process 
nevermind I found the solution :D
Treat eaxh term as an independent function. Like this :
f(x) = x³
g(x) = 3x²
h(x) = -9x
i(x) = -7
Therefore, y = f + g + h + i
(I removed the (x) because it's too repetitive
hi! can someone help me with this problem?
h(x)=|15-9x|
If h(x)=48, find x.
Since (a + b)' = a' + b'
Using the power rule and differentiation of a constant, you can calculate y'= (f+g+h+i)' = f'+ g' + h' + i'
help lol
D<0
hm?
where did this come from 😭
think it like this, if it had 2 distinct roots the the function had to cross x axis and become negative for values between them
Now to become non negative , it either touches the x axis or does not touch at all, means it can have equal roots or no roots at all
ahhhh okok i get this
|15-9x| = 48 ----> 15-9x = 48 , 9x-15 = 48
#1 15-9x = 48 -> 9x = -33 -> 3x = -11 --> x = -11/3
#2 9x-15 = 48 -> 9x = 63 --> x = 7
Oops I took 45 instead of 48
I guess you did a liiiiitle mistake there, sir :))
Yeah
it can have equal roots or no roots at all
is this based on the equations discriminant? im lost sorry
Yeah
when it has equal roots then it minimum value will be 0
Which is non negative
For example y=x²
for this discriminant should be 0
OHH is this the discriminant LOL
there can be another case when the function does not touch the x axis at all, it means it does not have real roots , for this D<0
yeah yeah
Yes
can i dm you LOL 😭
Yeah sure , am free for 15 mins
thank you!
I'm glad to be helpful!
i hate combinatorics help
4!×5c3 , -P-N -C - E -, A's can be filled in any three of the empty boxes , so 5c3, PNCE can be arranged in 4! , So 4!×5c3 @hardy hare
so 40 is the answer?
oh
@hardy hare what is the answer?
is it 240 😭 bro idk
Oh , I asked to confirm it , yeah I think it should be 240
oh okay thank you lol
Does this also consider the cases of something like AAPANCE
help required
I read the question again it says not all hmm , I did it such that every A is apart , well now I have do another case
Yeaa
I didn't do it yet
7!/3!- 5!
dude go away
can you do it then?
Well uh I made a mistake , lemme do it once again , total number of permutations will be 7!/3! , Which will include everycase, so to get the desired cases , we meed to substract the cases where all three A's are together , which would be 5!
dw i opened a ticket
@left knoll check this , and lemme know if it's correct
Kindergarten
ohhhh
Sadly am not Einstein ;-;
tbh i dont really know permutation combination and whatever it is 😅 i was just curious because i saw the possibility of 2 of the A's being together
Oh , ty for letting me know
duh why would i ask if i did
same and i hate it
part a ) divide and multiply by 2 , you would get 2 cos (60°+alpha)
From part a we can see that maximum value will be 2 &minimum -2
2(cos(60°+alpha)) =1
cos (60°+alpha) = 1/2
Now 60°+alpha = 60° or 300
So alpha = 0 & 240°
As I said am not Einstein , I have only 1 brain cell , but you look like a genius so maybe you can?
Then maybe you are blind
Can you help me with this
Cos A -cos A +cos A -cos A = 0
Indian
Lemme try this , jee advanced question I guess
Nah , how can I google integration questions lmao
Nope
Ik
No
Just ignore this guy please, they just want to pick a fight. We're all here to study
Yes it is.
Well tbh idc , what do you think, and try hard you cant even offend anyone , everyone is cringing hard rn at your texts
I will try it , if I will get the answer then will dm you , I have to revise integration first
Nah
Ok
ye i got it thx
Well what I did was I took (1-x)²& expanded it into (1+x²-2x)
And then I split this term
I think you can proceed like that
Well lemme try if it actually works or not
Nah i will try it later , it's better to do after revising the topic
@boreal torrent what grade are you in? When you are in college it is pretty easy
Hope this helps you @boreal torrent
and then, when you use normal integration, then it should me 22/7 - pi
help me please
A path 5m wide runs along inside a rectangular field. The length of the rectangular field is 3 times the breadth of the field. If the area of the path is 500 square metres, then find the length and breadth of the field.
PLEASE HELP ME anyone!!
I got length=100
so for breadth just divide that by 3
take it with a grain of salt tho im not sure
^
what specifically do you need to know in this
first part just plot the points second part take 2 points on the graph and find the slope by using y2-y1/x2-x1
3rd part H=(V^2)t/R
sin2x=2sinxcosx formula
yeah ik but i'm not able to see how they applied that on the rhs
now that term in the [ ] becomes sin4x
bruh
yah got it
no problem 😊
man i sure am grateful
@hollow mauve conver cosx = sin (π/2-x)
sin^-1 (sin (π/2-x))= π/2 -x
Assume tan(z) = X
it would become , z .(π/2-tan(z))sec²(z) dz
Oh
Lemme actually try then
It will be a lot easier if you just open 1-x^4 as a2-b2
I just thought of it like this , and it was working fine
It would cut with the denominator
Yeah, will try again! Appreciate it :)
@hollow mauve i dont know what level of math he has, so i tried the brute force one
Hahah okay!
besides its not 1-x^4 but (1-x)^4
Oh
Shit
Sorry
🤦🏻
Hey but I dont understand the first step of your integration
thats why i used polynomial division in order to break that integral up
My mind tends to simplify things a lot 😂
simply use binomial fomula und then transform
Oh
Never thought of this way
Yes yes
Alright thanks!
and after that, you have nice tan^-1(x) which has connections to pi
i hope he understands, what i tried to do xD
he didnt respond so ill wait
Same I am a jee aspirant as well
ah nice
Hyped up exam for science students
Very famous for being tough in foreign countries as well
i wish you luck then 😄
Do you have like old entrance exams?
So you can practice @hollow mauve ?
Because often, you simply take a closer look at these and then you basically know, what they are trying to aim for
Yeah I tried it , it is becoming extremely lengthy , so I just left it
I will dm you if I will solve in much more simpler way
@hollow mauve could you try send it again but this time rotated?
I can try and solve the integral
Are you allowed to use complex numbers for sin and cos?
Well you will still get the answer , I tried again , it is not too lengthy
.
someone speak spanish¿
need some help with this problem please
seems like asinh(a) would be the answer but I'm not quite sure
in trigonometric equations i am not able to understand where u take the x = 2n pie +- a and when to take it as (2n+1)pie/2
can someone explain it to me how it works?
I deleted my whole answer because I'm dumb and thought I was wrong.
I got the equation a sinh(a) = cosh(a)
How I got it :
- calculate tangeant fonction f(x) = mx + p knowing that it goes through (a, cosh(a)) and (0,0)
- You get f(x) = (cosh(a)/a)*x
- cosh(x) and f(x) are tangeant, and therefore have equal derivatives at x = a
- Knowing that (cosh(x))' = sinh(x), you get sinh(x) = cosh(a)/a at x = a
- Finally, you get sinh(a) = cosh(a)/a, which is equivalent to : a sinh(a) = cosh(a)
Quentin! (눈_눈;) you are not dumb. You are like the smartest person ever.🙌🏻
Let's be real, I'm not lol
I'll try it in 2h (if I don't forget to do it so don't rely to much on me :P)
But I can already tell you that the diagonals are perpendical (due to the symmetries in the triangles in the kite)
And that Q = (2m, 2n) where (m,n) are the coordinates of the intersection of the diagonals
Maybe a solution would be to get 2 equations you need to solve for x and y :
RQ= PQ
OQ = PR
(notation : OQ represents the linear function that goes through O and Q)
(҂⌣̀_⌣́)in my eyes you are!
slope of line oq =-1/slope of PR
=1/2
Equation of OQ = y=x/2
distance from 4,0= 4(isoceles triangle)
And Q lies on y=x/2
Solve to get positive values of x&y
hey does anyone have hyperbola notes for jee?
If it helps
Hi somebody can help me with this?
Sorry for the spanish hehe
I don't know how solve the second question
If You know a vídeo, please share
thanks for the help Quentin!
one question tho, how did you find f(x) (the second step)
To find f(x) you have to find m and p. You are given that the function passes through (a, cosh(a)) and (0,0). The parameter m specifies how much f(x) changes for a change in x. So you can find m by dividing the change in y by the change in x for both coordinates. So m = (cosh(a) - 0) / (a - 0) = cosh(a)/a. Finally you can find p by filling in one coordinate in f(x), for example (0,0). We know that f(0) = 0 must be true, so f(0) = (cosh(a)/a) * 0 + p = 0. That means p = 0.
ahh I got it. thank you!!
bezout theorem
Anybody know what i could do here?
is the three lines = ? cause if yes then i can try solving it @modest compass
Yeah i think so
okay i'll send it in sometime
its not equal
then what is it
Wait it isn't? I've always treated it like it was oops
?
@modest compass 1+cos^4x-sin^4 x and 2cos^2x are congruent
What does congruent mean?
the remainder congruent thing
so they are triangles
no..
congruence doesnt always refer to triangles
search up modulo congruence
if u think they are equal all the time then uh
which country are in from
search up modulo congruence and u will see the same sign
idk all im saying is that i learnt something like this in school and its different from what you are saying
dude you need to leanr what is being taught
i see i don't know about that
does anyone know how to complete the square fo 2x^2+5x-8=0
factorise
u still need help?
ok so im assuming u dont
thankyou
hii i dont need help anymore, just ealized i didnt need to do it
thank you for checking back!
sorry for the ping but if ur wondering how to do it, u should try making it factorizable. which in this case, i multiplied the whole equation by 2 (and 0x2 = 0) so that 4x^2 is factorizable (4x^2 = (2x)^2). so i have the equation 4x^2 + 10x - 16 = 0. in these equations where u have to complete the squares, u usually have to make it under the form of (a+b)^2 or (a-b)^2 or anything with a power of 2. here i see that I already have 4x^2 = (2x)^2 and I want to factorize 10x. as known, (a+b)^2 = a^2+2ab +b^2, where a in this case is 2x. so 2*(2x) * b = 10x. => 4 * x * b = 10x -> b = 10/4 = 5/2. and then we want (5/2)^2 = 25/4, but we currently have 16. so the equation turns into 4x^2 + 10x + 25/4 - 89/4 = 0. => using a^2+2ab+b^2 = (a+b)^2, 4x^2 +10x + 25/4 = (2x+5/2)^2 => (2x+5/2)^2 - 89/4 = 0 => (2x+5/2) ^2 = 89/4 => (2x+5/2) = either sqrt (89/4) or - sqrt (89/4), which are (sqrt 89)/2 or - (sqrt 89)/2. thus, x = either ((sqrt 89) - 5)/4 or - ((sqrt 89) - 5)/4
sorry if my explanation is still obscure lol
Can someone please help me with this question?
a + b + c = 23
a + b = c + 3 <=> a + b - c = 3
0.5a + 0.2b + 0.1c = 5.10
These are the three equations you need to solve to get a, b and c
Thus, if you represent the system with matrix, you get Ax = b where :
1 1 1
A = 1 1 -1 (coefficients of unknowns)
.5 .2 .1
x = [a, b, c] (the vector of unknowns)
b = [23, 3, 5.10] (independant terms)
@ruby tinsel From there, you can apply the Gaussian elimination you've learnt
(Hint : your answer should have c = 10, you can easily verify that using the first two equations)
Ohhhh I understand it now!! Thank you so much!!
where do u need help?
if you need help dealing with fractions, then multiply so u have common denominator
yeah multiply to have common denominator
i can solve with inequalities but whenever you switch sides a negative nmber then u switch the inequality sign
i dont understand still
You just treat the inequality as an equal sign, unless you multiply or divide by any negative number, then you flip the inequality around
yep!
yeah for this one you don't have to
As long as you keep the rule in your mind for a while it'll become natural
do u know the formula a^2-b^2 = (a-b)*(a+b)
you multiply so u have common denominator
the answer is 2b/a^2-b^2
i keep getting 2ab and not b
I am having some derivation/deduction issues with a thermodynamics problem. I want to solve for V2 but cant get it to match with the factsheet. If anyone has the time to explain it to me that`d be appriciated:)
guys, i need help. i got an exam tomorrow and i don't know how to solve this question. it's starting to chip away at my mind slowly the more and more i try with my friend over discord. help us out mate, im sure youse are smarter than the two of us combinedddddd.
Send me a dm for the ping, I'll try to do it when I'm done working
aw cheers mate, just in case if anyone else is down to hop in a call with me and help me figure this shit out i'd greatly appreciate it.
Radioactive decays are first order reaction
And half life of 1st orser reaction is 0.693/k
Find k then substitute in t=2.303/k log(10/10% 10g)
Is the time 79758 years
Let m0 be the initial mass of plutonium-239 (in g), t1 its half-life (in years) and t the time (years)
Let M(t) be the remaining mass of plutonium-239 at time t (in grams)
Using the function of exponential decay, you get :
(there's a mistake, I wrote M(x) instead of M(t))
The question gives you m0 = 10, M(t) = 1 (=10% of m0) and t1 = 24000
This gives you the following equation, that you need to solve for t :
My answer is different from @mossy fjord's, so one of us (or both) must have made a mistake
@fierce oasis
I might have made some mistake in taking the logarithm value.
But the formulas of chemical kinetics should apply on this question
But it was cool! Different approaches to the same question
@formal iris help me
can someone help me with this
Bit of a late response, but what you want start with is finding the minimum value and maximum value that y could take
i know this is irrelevant but I love your handwriting
hey is anyone good with hyperbola, please dm me
hello, can anyone help me with this: the sides of parallelogram are a=23cm and b=11cm, the lengths of the diagonals are in ratio 2:3, I need to calculate the diagonals. Pls help
Thank you so so much!!
no problem @floral marlin if you find any question difficult then just google it you'll get similar question then you can apply the formula and do it
Smart thinking haha thank you, I was stuck on this question for a long time haha
Oh naiss
Hey I'm taking the August sat does anyone have any tips
Hello! is there anyone who knows how to write in Latex?
Can anyone help solve this Differential Equations question?
IM STUDYING FOR SAT
AND FORGOT HOW TO DO THIS BASIC ALG 2 PROBLEM
PLS HELP
the answer is 4x-3 but idk how
f(x) = 3-2x
for f(f(x)) you replace the x in the f(x) with another f(x)
so 3 - 2x becomes 3 - 2f(x)
Yup, what's your question ?
@minor rapids
TRANSLATION: Find an equation of the spherical surface whose center is contained in the line r: and goes through the points A and B
nevermind, already did it lmao
What's the meaning of j ?
its just i
Oh okay
For the equality to hold, both real and imaginary parts must be equal
That gives you two equations :
32-8a = 0 (real parts)
0 = 7-a-b (imaginary parts)
From the 1st equation, you get that a = 4, and when you substitute that into the 2nd equation, you get b = 7 - a = 7-4 = 3
Therefore, a=4 and b=3
@sage cobalt
=infinite ?
for large x, you can disregard the +5 and just write it as 5*(4/3)^x, which as x approaches infinity also approaches infinity
I'm struggling to find the meaning of "is inverse" in your question
And there may be a typo, since it's odd to separate -3mx² and -9mx² instead of keeping it -12mx²
6 and 7
I hate word problems with my whole heart
I think my phone is glitching
Lol
Oh ma gawd I feel so dumb rn
Thank u smmmmmm
Your handwriting is beautiful idiot!
It's still beautiful
Find the distance from point Q = (10,2) to the
line L: 2x + y - 7 = 0
can someone help me with that problem?
- Find the function f(x) = mx + p, the graph of which is perpendicular to L and goes through Q
- Find the intersection between L and the graph of f(x) at point P (a,b)
- Use the distance formula : dist(Q,P) = sqrt[ (10-a)² + (2-b)² ]
Hint for 1 (if you struggle too much) : ||imagine that the slope (derivative) of L is equal to k. For f(x) to be perpendicular to L, you need to use m = -1/k ||
@brave vapor
thank you so much
Hi, I was wondering if someone could help me with this, I don't know how to do it, is function of function or co-function
this is the only example I have to do it but I don't understand:(
you solved it correctly though, what's wrong?
oh that's an example for you to understand. for f(Q(x)), imagine 3x+2, but instead of x, put whatever Q(x) is. so it'll become 3(4x^2-5x) + 2
from there, simplify it
If you dont understand dm me
Answer with explaination please
I don't know what to do in next step , is this correct ??
Trigonometric functions aren't related only to right triangles ; they're primarily linked to angles
Therefore, you need to find the value of angle BAC to be able to find sin(BAC), cos(BAC) and tan(BAC)
To find BAC, you might want to use the sine or cosine rules in arbitrary triangles (here : https://revisionmaths.com/gcse-maths-revision/trigonometry/sine-and-cosine-rule), since you already have the measures for all the sides and you know that two angles have the same value (isosceles triangle)
⬆️ I'll be honest with you, I won't go through the whole solution, because I'm not that fond of geometry, but here are the main steps to solve the problem
ty friend, i will try to solve now
it seems ok to me
ty bro
its of trignometric equations
do u know how to convert radians to degrees?
id prefer to solve it in degrees for simplicity but anything works
then u identify the special triangle
if u learnt ratios in 45-45-90 triangles then u can hence find the trig ratios of it
and the coordinates x,y of point A are respective to the cosine and sine of the angle pi/4
yes
u read yet?
yes
so if i do cosine that’s is adjacent hypotenuse right
but how do i know what the side lengths are
its the ratio
u dont need the side lengths because u should be able to recognize the special triangles
have u learnt ratios in special triangles yet
np
means
ohk
I am supposed to factorise this using the remainder theorem. Any idea where the value of x=2 came from?
it comes from the Gauss's theorem. It says that for any polynomial with coefficients in Z (integers) if it has any root in Q (rational root) it must be of the form p/q where p is a divisor for the independent term and q a positive divisor from the principal coefficient.
In this case p could be +-1,+-2,+-3,+-6 and q 1 or 3, so trying the differents combinations you arrive to 2, spoiler: ||also you arrive to -3 and 1/3||
why would this be 25x24? i don’t get it
for the first card marie can give 25
one of the 25
and after she gave it
she got 24 left
so she have 24 more choices
<=> 24x25
okay, thanks
Hi everyone, I am looking for a colleague we can support each other, if anyone thinks, please write, thank you
Hello everybody. I am currently looking into the statsmodels library, namely statsmodels.formula.api.ols. I read the documentation, it seems everything is clear, but at the same time, no. (i'm a little dumb person lol)
In short, I will be glad if someone can help with understanding the R-style formula, or send a link to useful posts. Have a nice day everyone. thanks
#python
since tan(pi/4)=1
The two sides are equal and the hypotenuse is 1 so
1=x^2 +x^2 (assuming the side length to be x)
2x^2=1
x=1/sqrt(2) [ we dont take the negative value since its the first quadrant]
phhh ok thanks
i already helped him tho
I gotchu
seriously dude just expand and solve:
4x-14+8x+6=112
12x-8=112
12x=120
x=120/12
x=10
Is this guy like elementary school
yeah maybe
1st one B 2nd one D
thankyou so much btw are you good in organic chemistry?
k
Can anyone help me number 21?
anyone pls help me with this! really appreciate it!
The answer should be 'x³'
On the left hand side, you take a summation of (1³ +2³+ ....+n³) under the common denominator n⁴
Which gives you (n.(n+1)/2)² on the numerator and n⁴ on the denominator
Solving for the limit for n -> inf
You get 1/4 on the LHS
Integration of x³ on the given parameters gives 1/4
Can somebody help me?
thank you so much for answering! but how to get (n.(n+1)/2)²?
That's a general formula for summation of first n natural numbers
It's general enough that it can be used without stating its proof
But I'd you're curious about the proof, you can look it up
alright! thanks a lot!
does anyone know how to get this ans? kindly explain it~thanks!
sorry if it looks confusing
the expression is the summation of n rectangles under the e^x curve
so as n approaches infinity the total area of all the rectangle is exactly the area under the graph from 0 to 1
oh oops didnt realize its just a geometric progression with common ratio e^(1/n)
the ans should be the last one, am I right?
the last one here ?
yea
np :p
anyone willing to allow me to send them questions or theory i'm struggling to grasp/understand? <<a level math>> external candidate so no teacher help. pm if u can
hi! can someone help me with this problem? “ write a linear equation in slope-intercept form with the given information. slope=4/3; passes through (-5,-6). thonk uu : )
i can help
thank you!
you can just select that point that the equation passes through which is -5,-6
do u know rise over run?
slope = rise/run
noemi
so u basically rise/run until u get the y intercept
hence u have y = 4/3x+y-intercept
the y intercept here is 2
ooh okay i understand now. thank you
npnpnpnpnp
Hi can someone help me with this question, I don't understand why dt/dx is less than or equal to 0?
Need help with part f, thanks
Additional info that may help^
-1 does not satisfy the equation so how come (D) is the answer?
If anyone can help, please.
(A) is actually the correct answer but when I looked up, they say solve it to give (D)
Hey @pulsar turret
I think you might have written the quadratic equation wrong when solving for x
Check with putting the options in the question directly, 200iq 📈😂
hey...i haven't studied math for 2 years but i have it in my course now (basically stuff like linear equations) so if anyone can clear up my doubts that'll be great . Thanks
Great idea if options are available
Hi ! Whether your questions are about general concepts or precise exercises, you can share them in this channel, and people will explain them to you. (If the answers to your questions happen to be long, you might expect to receive them in your dm's, to prevent flooding this channel 😄)
cool thx
Yeah..
So, what're your questions?
nothing atm but im sure ill have a lot of doubts as my classes go by, So i just wanted to know if ill be able to get help here. Thx
ask me
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Some words on the left and right of the screen are cut out. We don't have access to the whole question.
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When asking for help, please translate the question for non-French speakers.
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Considering the time of the year and that you're on a UCL-related website, you're most likely currently taking an online exam. If so, you may have skipped reading rule 5 of #welcome
Okay my bad
Good luck anyway
Thanks but it was to help a friend
As the example shows, the geometric mean of 2 numbers (there's a slight difference when dealing with 3 or more numbers) is just the square root of the product of these numbers
is there any way to solve this algebraically?
quentin what do u think
therer are 9 variables smh
is trying out the only method
this problem is sus
There is indeed an algebrical way to solve this
Give me some time to write it on paper
u there quentin
I m scratching my head over this Q :p
i am not sure if it could be solved algebraically
its a question from nrich maths
the solution they provided were just students tryin all sorts of combinations
It definitely can be solved algebraically
like it feels like a,b,c... will get cancelled out somehow
Srry i couldn't do it.
ok no problem thanks for trying it out
can help with this
is that a test
I'll be honest with you, this question just reminded me of how bad I am at discrete math problems
is it just trial and error?
this is bs
i think trial and error is the only method
Suppose b+d+f+h is divisible by 5.
Min (b+d+f+h) ⇔ 1+2+3+4 = 10
Max (b+d+f+h) ⇔ 6+7+8+9 = 40
B+d+f+h is counted twice => totals of circles are Min or Max when b+d+f+h is Min or Max.
=> Min (all circles) = 1+2+3+4+5+6+7+8+9+Min (b+d+f+h since it’s counted twice) = 55
Max (all circles) = 1+2+3+4+5+6+7+8+9+Max (b+d+f+h) = 85
Case 1: We take min (b+d+f+h) ⇔ b or d or f or h = 1 or 2 or 3 or 4
=> a or c or e or g or i = 5 or 6 or 7 or 8 or 9
From the problem we could identify that a+b = b+c+d = d+e+f = f+g+h = h+i
=> a=c+d
b+c=e+f
d+e=g+h
i=f+g
here is my process so far
But I quickly wrote a very unoptimised program to get all possible solutions, so that you maybe could find some pattern in these
Here they are :
4 9 1 3 8 2 5 6 7
5 9 2 3 4 7 1 6 8
7 6 5 2 3 8 1 4 9
7 6 5 2 8 3 1 9 4
8 3 7 1 6 4 5 2 9
8 6 1 7 4 3 2 9 5
9 2 5 4 6 1 7 3 8
9 4 1 8 3 2 5 6 7
ah
yes the solutions
so
ill just say
i did
"trial and error"
and i got that
PRO
BIG BRAIN MY CLUEBERRY FAYGO
You don't need to lie for that
does this sound good?
Just be honest, write that you couldn't find a proper pattern and that trial and error didn't give you any satisfactory solution
No problemo
@ember kernel wait are those all of the solutions
this is bs problem imagine if my teacher doesnt grade this i force her to grade
Nah, for such a problem, that thoroughly relies on trial and error, it would be more than unfair to grade
I got them using a Python program I wrote, not by hand
Ah ok
that is the property of absolute value?
I'm out of ideas on how to start
do u know what is absolute value
is anyone here good in mathematical logic?
Do I multiply only pairs of numbers when trying to get a number before the root?
So if there wasn't that one 3, I would only do 22 and its root is 2 so I would write 2√35*7?
I mean 2 * 2 but discord messed up
we write it out like that because we can take advantage of sqrt(a*b) = sqrt(a)*sqrt(b)
and we use the pairs of numbers because sqrt(a*a) = sqrt(a^2) = a
Can someone explain to me why k< -8 as we just brought -8 to the other side, we didn't multiply or divide by a negative number, so the sign would remain the same but they have reversed the sign
Anyone knows why the sum of the nth line of this triangle of consecutive odd numbers is simply n^3 ?
Like, for the 3rd line it'd be 7+9+11 which is 27 which is 3^3
for product of two integers to be positive, either both of them have to be positive or both of them have to be negative.
k(k+8) > 0 for k>0, also
k(k+8) >0 for k<-8.
If you look closely, you'll see that the algebrical mean of each line n is n^2. Then, to get the total sum of the n items (odd numbers) the line, you multiply the mean by the number of items. Thus, you get that the total sum is n*n^2 = n^3
Wow good freaking catch, thanks ! Simple curiosity, how'd you arrive to that conclusion, did you simply observe the triangle and it popped in your mind or ?
The answer is -2 but I'm not sure if I did the process correctly?
since wouldnt it be (-4)(0+2) which equals 0; therefore, the answer would be wrong?
hmmm I'm a little rusty in maths but I don't think you can remove the h at the line before the last one. Plus you don't really need to, you're calculating the limit when h tends toward 0, -2h + h^2 -8 then tends toward -8, and -8 divided by h then tends toward -∞
yeah, I figured out my mistake
at the second line,
rather than [9-12-1]-[-4] which equals 0
ive been doing it without that brackets, thinking it was 8
oh yeah then you were right about the -2 limit 🙂
Anyone?
f(0)= c = f(-3+3)= 10, then
f(1)= a+b+c= f(-2+3)=2,
f(-1)= a-b+c= f(-4+3)= 24,
solving for a and b gives, a= 3, b=-11, so
4a-2b+c= 44.
Any help pls?
use pascal triangle to expand (a+b)^n
i think
thats my approach its definitely one of the worst
Convert into spherical coordinates
From there, to get z^10, put mod(z) (the norm) to the power of ten, and multiply arg(z) (the angle) by 10
But are you sure that i is part of the square root ? Because, if so, you must first convert the complex into the format a + bi
(But given the difficulty and nature of the question, I doubt this is the case)
Thank you
Nais
Can someone explain where does the square root of the first x+4 goes?
the second term has extra square root of (x+4) in the denominator, so you multiply the numerator of the first term with square root of (x+4).
But didn't the denominator cancel out the the square root using the square and moves the power(-1/2) x+4 in the numerator down to the denominator to have another square root?
Yes, but (x+4)^(-1/2) is only in the second term, so to move it down to the common denominator, you have to multiply numerator of the first term by (x+4)^(1/2).
i have my maths exam on oct 29th /2nd nov it's Pure maths 3 and mechanics 1 (A2) like highschool level maths . so i am looking for advice on how i need to study to get a good grade considering i failed my last exams on this subject . So please i'm really stressing out on how to go about this . i could use all the advice i could get
General tips :
- You've still got 2 months to study and get ready. Don't panic, that'd be enough time to study the course twice if needed
- There's no shame in asking questions, and there's no such thing as dumb questions. If you don't feel confident to do so in front of others (although some of them would most likely actually like to get the answers to your questions too), ask them at the end of the class if you have time.
- Making a summary is very helpful and serves as a big role in the learning process. You can even ask you teacher to review it. If you're too shy, you can also ask a friend to do that latter part for you. Teachers' role is to help students after all.
- Practice. A lot. Because there's no better way to remember a formula and how to use it than actually getting familiar with it through many different exercises. Try to adapt the difficulty as well as you get better
Finally :
- Don't get stuck for hours on a problem if you can't concentrate. Take a break, go outside, read the theory again or ask this channel for guidances on how to solve it. But do not just stare at it endlessly
Unfortunately, I don't know what's studied in that "Pure maths 3" course, so I can't give you any precise tip regarding the matter itself
I don't know how to conclude, so I'll just add : never give up !
ye and ask me for help
Ask anyone* for help ^^
Sorry for the late reply.
It just occured to me that each line had """symmetrical items""".
Take line 3 for example, while searching for patterns in the triangle that could explain the n^3 thing, I didn't look at its items as 7, 9 and 11, but as 9-2, 9 and 9+2 instead, which gave the obvious mean = 9 = 3^2. From there, I quickly checked the result with lines 2 and 4 and got my conclusion from there
isnt that peroperty of pascal
Tbh I can't remember what this property is precisely
Idk what that is
Was answering someone else's message
american mathematics competition
like the amc8 amc10 amc12
As my role says, I'm European, but I did take part in regional competitions
hmm oke but the competition is worldwide we also do it in asia
Oh I had never heard about it.
But tbh, I think it's kinda off topic in this channel
ok
the topics in Pure Mathematics 3 Paper are;
3.1 Algebra
3.2 Logarithmic and exponential functions
3.3 Trigonometry
3.4 Differentiation
3.5 Integration
3.6 Numerical solution of equations
3.7 Vectors
3.8 Differential equations
3.9 Complex numbers
also thank you for the tips !! i liked to add
bro i'm so lost tho
me too
i gotta review my integrals and derivatives again
its been two years since i done that stuff
4.1 Forces and equilibrium
4.2 Kinematics of motion in a straight line
4.3 Momentum
4.4 Newton’s laws of motion
4.5 Energy, work and power
^ for mechanics my other paper
does paper mean "syllabus"
well yes the topics for the specific exam
in maths i have 2 sub exams , one is pure math also known as calculus and the other exam is Mechanics
honestly man i'm also lost because i have to self study the syllabus . i don't have school
anyway thank you alot for the tips, i needed at least some guidance to get my mind straight
the topics in your syllabus
are you learning all of the topics in you syllabus for the first time
or are some review
cuz if u already did pre-calc, then it seems like a pretty standard clauclus course
yes ive done them before but it was months ago so now they're really vague to me
here's the syllabus if you guys wanna check it out
Is this right and if so why do i extend the 4 with times 2 instead of + 2?
yea u right, +2 would not have gave u the same base of two that you need to solve
But why is that? i dont understand it
@winged coyote "+2 would not have gave u the same base of two that you need to solve" why?
cus normaly 2^2 is 4
why is it 2^X x 2 instead of 2^X + 2 when the rule says This "a^2 times a^2 is a^2+2" anyone feel free to help me understand 😄
ok
square has all sides equal
yes
mhm
cant we do my way as square has all sides equal?
u need to find coordinates of a b c d not lenghts of the sides'
ahh ohh i need to read question nicely smh
wait so can u show the process
like what do u find first '
what do u find next and so on
guitars question?
uve still got time bud ul learn
i just learned this last week
equation of ac is 2x+y-5 = 0 <=> y = 2x-5 => slope of y = 2? meanwhile ac's slope is ad/ac = 1??
i am confused
i mean
-1
ad/ac = -1
rise over run not the fraction
uhh
anyone
can we not corelate?
guys
pardon?
teh distance from midpoint ac to a,b,c,d is sqrt 20
whom ?