#math-help

1 messages · Page 34 of 1

cyan night
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they arent?

left knoll
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h should come first then g

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no?

cyan night
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no

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h is intersection between ac and mn

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guys

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is anyone there

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indian grinder how should i use ∠AHM = ∠BGN

left knoll
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mahn is this hard or only i am finding it hard?

cyan night
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its grade 8

left knoll
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lolllllll

cyan night
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uh

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whats ur approach

median turtle
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I just entered the server and saw this problem floating here

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@cyan night Have you learnt euclidean geometry?

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Its needed for this problem

left knoll
cyan night
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what is that

median turtle
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Oh

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wait

cyan night
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i dont think so and it doesnt need it

median turtle
cyan night
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my teacher made it possible for grade 8 knowledge

left knoll
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@median turtle hey is the figure correct?

median turtle
cyan night
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he is

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🤔

median turtle
cyan night
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what

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it is possible

median turtle
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Ok let me explain

cyan night
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😦

median turtle
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It may take some time, but it should be the solution

cyan night
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okay

median turtle
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what is your figure?

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reply to the message where you sent it

cyan night
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this

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i added point P

median turtle
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basically

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what you gonna do is

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make a random quadrilateral

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let me fix one up quick

cyan night
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ok

median turtle
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Yes

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the E is point N

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because ∠AHM = ∠BGN

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we can say that

cyan night
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what are those labels lol

median turtle
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Yeah I drew it on a screen

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like on a webpage

cyan night
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ok

median turtle
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so its kinda bad

cyan night
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ok

median turtle
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If you see the drawing closely

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You realize that by dividing the quadrilateral by AC

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You get 2 triangles

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so if you can prove that those are congruent

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you can say that AC = BD

cyan night
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yeah

median turtle
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since ∠AHM = ∠BGN is given

cyan night
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so

median turtle
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try it yourself first, proving the congruency of ABC and ADC

cyan night
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uhh

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im having a different approach

median turtle
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actually no, its ACB and BDC

median turtle
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like explain

cyan night
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here is my shape

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mn is parallel to dp

median turtle
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ah ok

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I realize

cyan night
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wait so doesnt that mean g is the midpoint of bd?

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oh nvm i thought g,h,n are alligned

cyan night
median turtle
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Huh.

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Your teacher made it pretty easy

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Consider the quadrilateral a square

cyan night
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what

median turtle
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now draw it and prove its congruency using SSS rule

cyan night
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no i am figuring out in a different direction

median turtle
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Ok then, you're on your own

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I helped you with my way

cyan night
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ok

ember kernel
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I'm at work. Rely on others for now ^^

cyan night
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ok

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im self relying

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wait @median turtle are we considering that ac = bd or ahm = bgn

median turtle
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use both of them

cyan night
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what

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it said that prove ac = bd if and only if ahm = bgn

left knoll
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I forgot 😭

twilit crane
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Hey

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@cyan night

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I got it

cyan night
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me too

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its actually easy lol

twilit crane
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It's thales

cyan night
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yeah

twilit crane
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Yes too easy

cyan night
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also known as midline of a trapezium

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do u know midline of trapezium?

twilit crane
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Yes

cyan night
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yeah so basically what i did was i drew the midline of trapezium abcd

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the midline connects the midpoints of ac and bd so its also the intersection of the diagonals of the two parallelograms

twilit crane
cyan night
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what

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oh

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in this problem i used both

twilit crane
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Qf right

cyan night
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yeah if thats how u named the midline of trapeziu

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qf = 3+5)/2 = 4

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qf is also the midline of triangle mnk

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qf = 1/2NK => NK = 8

twilit crane
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Yes

median turtle
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remember?

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find all possible cases of x y and z such that

candid mothBOT
median turtle
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help

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Find all possible cases of x y and z such that the equation

cyan night
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algebra

median turtle
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Yes help

cyan night
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i remember already doing it

median turtle
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yea so help me?

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please?

cyan night
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but i dont remember how i did it

median turtle
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bruh

cyan night
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because i never concentrated in my algebra class

median turtle
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@left knoll

median turtle
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The question is: find all cases of x y and z such that the equation

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nevermind

cyan night
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u stillneed help?

left knoll
cyan night
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just algebaically simplify

ivory pumice
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Hmm

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Did you solve it? Or still need help?

cyan night
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i solved it

ivory pumice
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Ok

cyan night
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i neatly solved it

ivory pumice
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Ok

cyan night
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do u want to know the solution or do u know how to do it

ivory pumice
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Nah I did it

cyan night
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👍

ivory pumice
median turtle
swift ridge
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Hello

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I need help

median turtle
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hi

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send the question here

swift ridge
median turtle
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can you please translate this?

swift ridge
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I need to sole this

median turtle
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this is a test?

swift ridge
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Solve the following initial value problems

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Old exam

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You know or not

short rover
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hey someone break mid term in 3x^2 - 4√3x + 4

ivory pumice
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It is a perfect square@short rover

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(√3x -2 )²

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3x²-2√3x -2√3x+4

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√3x(√3x-2)- 2(√3x-2)

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(√3x-2)²

stray musk
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I have been stuck on this for a fat while

ivory pumice
swift ridge
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Yes ok no problem I what to see the right answer

ember kernel
# stray musk

(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

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That's called the comparison theorem

left knoll
ember kernel
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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)

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@left knoll

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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)

ivory pumice
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and put y(-1)= 1

ivory pumice
ivory pumice
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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

tawny ingot
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Hello Im currently in middle school and would like to learn algebra 1, 2 and 3 online.
Does anyone here knows any good sites?

hearty tapir
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There are amazing websites that are suitable for learning math, physics etc. like KhanAcademy and Openstax.I recommend them @tawny ingot

stray musk
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Does anyone know how to do this?

formal heart
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Can someone help me with this? Its Simplifying Complex Fractions

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This is what I have so far not sure if its correct though

cyan night
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for these problems, just simplify them into a common denominator in both fractions and u can solve it

hearty tapir
cyan night
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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◦

steel plover
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can someone help me out with a?

timber scarab
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B part

swift ridge
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Guys I need someone who knows (matlab)

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I need to ask about something

zenith quarry
zenith quarry
timber scarab
zenith quarry
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Can u explain because , I didn't understood !
I have just started doing derivatives .

mossy fjord
steel plover
mossy fjord
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Glad to help !

slow cipher
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anyone knows how to solve this?

dire dagger
timber scarab
next viper
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ayo

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in exam rn

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idk how to do thht

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help

left knoll
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just a sec

left knoll
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use that and also use (a-b)^2

next viper
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-;

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dint understand

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my exam

left knoll
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oh this is an exam

next viper
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question

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stuck LOL

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bruh

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iam dead

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bruh

left knoll
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i cant help you with an answer

next viper
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;

left knoll
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use the identity

next viper
left knoll
# next viper

i think a - is like the elements in the universal set which are not in a but im not sure

next viper
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ayo

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If y-1/y =9 find the value of y3-1/y3​

peak gale
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multiply by y , find the roots of the polynomial then inject in the relationship : y^3-y^(-3)=...

timber scarab
cyan night
steel plover
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can someone help me out with this problem?

floral marlin
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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!

left knoll
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If possible can you send pic of the diagram

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Try calculating value of sides using angles and then use Herons formula

floral marlin
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i did right that and also tried with the height

twilit crane
# floral marlin

Bro I think the angles ąlpha and Beta are the ones on each end of the line a

left knoll
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BC= 12cos (beta) and AC= 12 cos(beta) cos (alpha) but those values turn out to be so small that triangles property is violated

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So, i guess we need to find suitable triangle and then calculate area

floral marlin
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ohh i see it now, I actually also turned around the angles

left knoll
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lol

floral marlin
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I'll try again lol Thank you!

left knoll
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Guys can someone from India who studies engineering or medicine please dm me

alpine escarp
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can someone help me guess what this function is

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the value on the y axis that's blurred out is 3

ember kernel
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y = -1,5x +3, thank me later

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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
hushed talon
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Does anyone know how can I turn this

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into this?

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Im stuck :c

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I need the process w_vergonha

hushed talon
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nevermind I found the solution :D

fringe heart
ember kernel
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Treat eaxh term as an independent function. Like this :
f(x) = x³
g(x) = 3x²
h(x) = -9x
i(x) = -7

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Therefore, y = f + g + h + i
(I removed the (x) because it's too repetitive

slate pawn
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hi! can someone help me with this problem?

h(x)=|15-9x|
If h(x)=48, find x.

ember kernel
hardy hare
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help lol

ivory pumice
hardy hare
ivory pumice
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non negative hmm means it can be 0 too, it should be D<=0

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D= 144-4×(-5+2a)×4

hardy hare
ivory pumice
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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

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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

hearty tapir
hearty tapir
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I guess you did a liiiiitle mistake there, sir :))

ivory pumice
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Yeah

hardy hare
ivory pumice
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Yeah

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when it has equal roots then it minimum value will be 0

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Which is non negative

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For example y=x²

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for this discriminant should be 0

hardy hare
ivory pumice
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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

ivory pumice
hardy hare
ivory pumice
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Yeah sure , am free for 15 mins

hearty tapir
hardy hare
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i hate combinatorics help

ivory pumice
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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

ivory pumice
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10×24

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4! = 4×3×2×1

hardy hare
ivory pumice
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@hardy hare what is the answer?

hardy hare
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is it 240 😭 bro idk

ivory pumice
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Oh , I asked to confirm it , yeah I think it should be 240

hardy hare
left knoll
proven orchid
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help required

waxen storm
proven orchid
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alpha was found as 60 degrees

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is that correct?

ivory pumice
proven orchid
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I didn't do it yet

ivory pumice
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7!/3!- 5!

waxen storm
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dude go away

boreal torrent
proven orchid
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can you do it then?

ivory pumice
# hardy hare oh

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!

left knoll
ivory pumice
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Kindergarten

ivory pumice
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Sadly am not Einstein ;-;

left knoll
hardy hare
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duh why would i ask if i did

ivory pumice
# proven orchid help required

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?

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Then maybe you are blind

boreal torrent
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Can you help me with this

ivory pumice
fringe heart
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Indian

ivory pumice
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Nah , how can I google integration questions lmao

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Nope

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Ik

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No

left knoll
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Just ignore this guy please, they just want to pick a fight. We're all here to study

boreal torrent
ivory pumice
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Well tbh idc , what do you think, and try hard you cant even offend anyone , everyone is cringing hard rn at your texts

ivory pumice
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Nah

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Ok

waxen storm
ivory pumice
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And then I split this term

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I think you can proceed like that

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Well lemme try if it actually works or not

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Nah i will try it later , it's better to do after revising the topic

frail geode
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@boreal torrent what grade are you in? When you are in college it is pretty easy

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Hope this helps you @boreal torrent

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and then, when you use normal integration, then it should me 22/7 - pi

storm horizon
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help me please

left knoll
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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!!

ivory schooner
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I got length=100

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so for breadth just divide that by 3

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take it with a grain of salt tho im not sure

sonic breach
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^

sharp ferry
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first part just plot the points second part take 2 points on the graph and find the slope by using y2-y1/x2-x1

waxen storm
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how did this happen>

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?

sharp ferry
waxen storm
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yeah ik but i'm not able to see how they applied that on the rhs

sharp ferry
#

did you get it now?

waxen storm
#

dude

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are u

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einstein

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thank you so much

sharp ferry
#

now that term in the [ ] becomes sin4x

sharp ferry
waxen storm
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yah got it

sharp ferry
waxen storm
hollow mauve
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A Lil help with 4(i) pls?

ivory pumice
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@hollow mauve conver cosx = sin (π/2-x)

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sin^-1 (sin (π/2-x))= π/2 -x

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Assume tan(z) = X

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it would become , z .(π/2-tan(z))sec²(z) dz

hollow mauve
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Yeah I tried that but got stuck in simplification

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😂

ivory pumice
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Oh

hollow mauve
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Maybe trigo formula was not clear

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Will try again

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Thanks

ivory pumice
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Lemme actually try then

hollow mauve
# frail geode

It will be a lot easier if you just open 1-x^4 as a2-b2

ivory pumice
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I just thought of it like this , and it was working fine

hollow mauve
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It would cut with the denominator

hollow mauve
frail geode
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@hollow mauve i dont know what level of math he has, so i tried the brute force one

hollow mauve
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Hahah okay!

frail geode
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besides its not 1-x^4 but (1-x)^4

hollow mauve
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Oh

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Shit

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Sorry

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🤦🏻

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Hey but I dont understand the first step of your integration

frail geode
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thats why i used polynomial division in order to break that integral up

hollow mauve
frail geode
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simply use binomial fomula und then transform

hollow mauve
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Never thought of this way

frail geode
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then you can cut out everthing that has the form 1+x^2

hollow mauve
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Yes yes

hollow mauve
frail geode
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and after that, you have nice tan^-1(x) which has connections to pi

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i hope he understands, what i tried to do xD

hollow mauve
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Well

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I understood

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He will too

frail geode
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he didnt respond so ill wait

hollow mauve
#

Same I am a jee aspirant as well

frail geode
#

whats that?

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Never heard that term before

hollow mauve
#

Its and entrance for engineering

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In india

frail geode
#

ah nice

hollow mauve
#

Hyped up exam for science students

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Very famous for being tough in foreign countries as well

frail geode
#

i wish you luck then 😄

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Do you have like old entrance exams?

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So you can practice @hollow mauve ?

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Because often, you simply take a closer look at these and then you basically know, what they are trying to aim for

ivory pumice
#

I will dm you if I will solve in much more simpler way

frail geode
#

@hollow mauve could you try send it again but this time rotated?

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I can try and solve the integral

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Are you allowed to use complex numbers for sin and cos?

ivory pumice
frail geode
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@ivory pumice could you send the trick?

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cuz i dont see it

frail geode
#

oh bruh

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Is someone here good at statistics?

mellow bramble
#

someone speak spanish¿

steel plover
#

need some help with this problem please

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seems like asinh(a) would be the answer but I'm not quite sure

waxen storm
#

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

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can someone explain it to me how it works?

ember kernel
#

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)
mossy fjord
formal patrol
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Can anyone help me with this? Should I convert this to classes?

covert anchor
#

how would i do this

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i tried so many times

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spent 1 hour on this thing

ember kernel
#

I'll try it in 2h (if I don't forget to do it so don't rely to much on me :P)

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But I can already tell you that the diagonals are perpendical (due to the symmetries in the triangles in the kite)

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And that Q = (2m, 2n) where (m,n) are the coordinates of the intersection of the diagonals

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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)

mossy fjord
ivory pumice
#

=1/2

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Equation of OQ = y=x/2

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distance from 4,0= 4(isoceles triangle)

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And Q lies on y=x/2

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Solve to get positive values of x&y

covert anchor
rustic sapphire
#

hey does anyone have hyperbola notes for jee?

left knoll
void badge
void badge
tardy crown
#

Sorry for the spanish hehe

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I don't know how solve the second question

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If You know a vídeo, please share

steel plover
steel plover
dark sorrel
#

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.

cyan night
#

bezout theorem

modest compass
#

Anybody know what i could do here?

pearl tusk
#

is the three lines = ? cause if yes then i can try solving it @modest compass

pearl tusk
#

okay i'll send it in sometime

cyan night
#

its not equal

pearl tusk
#

then what is it

modest compass
#

Wait it isn't? I've always treated it like it was oops

pearl tusk
cyan night
#

@modest compass 1+cos^4x-sin^4 x and 2cos^2x are congruent

modest compass
#

What does congruent mean?

cyan night
#

the remainder congruent thing

pearl tusk
#

so they are triangles

cyan night
#

no..

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congruence doesnt always refer to triangles

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search up modulo congruence

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if u think they are equal all the time then uh

pearl tusk
#

dude you are literally in middle school

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your role says that

cyan night
#

i learnt it already

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so u think im wrong?

pearl tusk
#

which country are in from

cyan night
#

search up modulo congruence and u will see the same sign

pearl tusk
cyan night
#

just search it up

pearl tusk
#

yea i looked it up

#

you're right

cyan night
#

for your information, equal is =

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ya they are different

pearl tusk
pearl tusk
#

ik i thought it was an error

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sorry

cyan night
#

no problem

#

its a little more advanced

pearl tusk
#

i see i don't know about that

sharp grove
#

does anyone know how to complete the square fo 2x^2+5x-8=0

cyan night
#

factorise

cyan night
#

ok so im assuming u dont

rustic sapphire
sharp grove
#

hii i dont need help anymore, just ealized i didnt need to do it

#

thank you for checking back!

cyan night
# sharp grove hii i dont need help anymore, just ealized i didnt need to do it

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

ruby tinsel
#

Can someone please help me with this question?

ember kernel
#

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)

ruby tinsel
tardy maple
#

how to do these type of questions

#

i cant wrap my head around it

cyan night
#

if you need help dealing with fractions, then multiply so u have common denominator

glacial robin
#

probably something like this

cyan night
#

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

tardy maple
#

i dont understand still

lofty arch
#

You just treat the inequality as an equal sign, unless you multiply or divide by any negative number, then you flip the inequality around

tardy maple
#

ah

#

so its like solve for x but more fancy

lofty arch
#

yep!

tardy maple
#

how do you know when to flip the sign

#

nvm

#

i got it

#

thanks

lofty arch
#

As long as you keep the rule in your mind for a while it'll become natural

glossy falcon
#

Hi guys I just discovered am stupid I can't solve (5) for some reason

cyan night
#

you multiply so u have common denominator

#

the answer is 2b/a^2-b^2

glossy falcon
#

i keep getting 2ab and not b

chilly light
#

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:)

fierce oasis
#

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.

ember kernel
#

Send me a dm for the ping, I'll try to do it when I'm done working

fierce oasis
#

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.

flint crest
#

May someone help me?

#

The question ask to simplify

mossy fjord
# fierce oasis

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)

mossy fjord
ember kernel
# fierce oasis

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 :

candid mothBOT
ember kernel
#

(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 :

candid mothBOT
ember kernel
#

My answer is different from @mossy fjord's, so one of us (or both) must have made a mistake

#

@fierce oasis

mossy fjord
mossy fjord
weary granite
#

@formal iris help me

sharp ferry
#

can someone help me with this

coral sierra
gleaming ridge
rustic sapphire
#

hey is anyone good with hyperbola, please dm me

rustic sapphire
floral marlin
#

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

pearl tusk
#

Here dude

#

@floral marlin

floral marlin
#

Thank you so so much!!

pearl tusk
#

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

floral marlin
#

Smart thinking haha thank you, I was stuck on this question for a long time haha

timid delta
#

Oh naiss

turbid stump
#

Hey I'm taking the August sat does anyone have any tips

gritty agate
#

Hello! is there anyone who knows how to write in Latex?

hardy elk
#

Can anyone help solve this Differential Equations question?

minor rapids
#

IM STUDYING FOR SAT

#

AND FORGOT HOW TO DO THIS BASIC ALG 2 PROBLEM

#

PLS HELP

#

the answer is 4x-3 but idk how

lofty arch
#

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)

ember kernel
dense wadi
#

@minor rapids

weak silo
#

TRANSLATION: Find an equation of the spherical surface whose center is contained in the line r: and goes through the points A and B

weak silo
sage cobalt
#

I need help

ember kernel
sage cobalt
#

its just i

ember kernel
#

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

left knoll
#

i need help

#

it's pretty hard

left knoll
#

help

left knoll
lofty arch
#

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

left knoll
#

yea is like 5*(4/3)^inf+5/(3^x)=inf+0=inf

#

tyyyyy <333

ember kernel
# left knoll

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

left knoll
#

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

brave vapor
#

Find the distance from point Q = (10,2) to the
line L: 2x + y - 7 = 0

#

can someone help me with that problem?

ember kernel
#
  1. Find the function f(x) = mx + p, the graph of which is perpendicular to L and goes through Q
  2. Find the intersection between L and the graph of f(x) at point P (a,b)
  3. 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

urban idol
#

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:(

steel phoenix
#

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

carmine viper
#

If you dont understand dm me

zenith quarry
#

Answer with explaination please

#

I don't know what to do in next step , is this correct ??

ember kernel
#

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)

#

⬆️ 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

vapid osprey
#

ty friend, i will try to solve now

limpid lantern
#

it seems ok to me

vapid osprey
#

ty bro

left knoll
median sapphire
#

its of trignometric equations

fast schooner
#

can someone explain how to solve this

cyan night
#

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

fast schooner
cyan night
fast schooner
#

yes

#

so if i do cosine that’s is adjacent hypotenuse right

#

but how do i know what the side lengths are

cyan night
#

u dont need the side lengths because u should be able to recognize the special triangles

#

have u learnt ratios in special triangles yet

fast schooner
#

ohh i see

#

i will have to review that then

#

thank u

cyan night
#

np

median sapphire
#

@cyan night

cyan night
#

no

#

refuse

median sapphire
#

means

cyan night
#

wdym

#

i refuse to do that

median sapphire
#

ohk

harsh schooner
#

I am supposed to factorise this using the remainder theorem. Any idea where the value of x=2 came from?

tidal galleon
# harsh schooner I am supposed to factorise this using the remainder theorem. Any idea where the ...

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||

faint citrus
#

Pythagorean theorem

#

@knotty totem

left knoll
#

why would this be 25x24? i don’t get it

cyan night
#

one of the 25

#

and after she gave it

#

she got 24 left

#

so she have 24 more choices

#

<=> 24x25

left knoll
#

okay, thanks

cyan night
#

np

#

any questions ask clueberry faygo

charred charm
#

can you help me with part c pls
part a 14.7m
part b 4.1m
i just dont get part c

left knoll
#

Hi everyone, I am looking for a colleague we can support each other, if anyone thinks, please write, thank you

arctic crater
#

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

sharp ferry
#

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]

fast schooner
#

phhh ok thanks

cyan night
#

i already helped him tho

rustic sapphire
#

help!!!!!!!!!!!

snow eagle
#

can some help 2(2x-7)+2(4x+3)=112

#

how get x?

silk charm
rustic sapphire
#

seriously dude just expand and solve:
4x-14+8x+6=112
12x-8=112
12x=120
x=120/12
x=10

snow eagle
#

thanks

#

also howyou find area

#

ik b x h but i still confused

rustic sapphire
#

33x

#

sub the value of x in this

cyan night
#

Is this guy like elementary school

rustic sapphire
#

yeah maybe

obsidian sage
rustic sapphire
#

thankyou so much btw are you good in organic chemistry?

obsidian sage
#

i dont take chem anm

#

so no

rustic sapphire
#

k

left knoll
#

Can anyone help me number 21?

crisp topaz
#

anyone pls help me with this! really appreciate it!

inland sigil
#

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

charred hedge
#

Can somebody help me?

crisp topaz
inland sigil
#

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

crisp topaz
crisp topaz
#

does anyone know how to get this ans? kindly explain it~thanks!

obsidian sage
#

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)

crisp topaz
obsidian sage
crisp topaz
obsidian sage
#

the rectangles have length of base = 1/n and height = e^(k/n)

#

there are n of them

crisp topaz
#

I see

#

oops ok..misunderstood

#

Thanks ya!

obsidian sage
#

np :p

azure lion
#

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

slate pawn
#

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 : )

slate pawn
cyan night
#

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

slate pawn
#

ooh okay i understand now. thank you

cyan night
#

npnpnpnpnp

indigo field
#

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^

pulsar turret
#

-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)

indigo field
#

Hey @pulsar turret

#

I think you might have written the quadratic equation wrong when solving for x

hollow mauve
# pulsar turret

Check with putting the options in the question directly, 200iq 📈😂

left knoll
#

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

left knoll
ember kernel
hollow mauve
ember kernel
left knoll
#

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

cyan night
#

ask me

tiny trout
#

Anyone knows how to find xj and fj ?

ember kernel
# tiny trout Anyone knows how to find xj and fj ?
  1. Some words on the left and right of the screen are cut out. We don't have access to the whole question.

  2. When asking for help, please translate the question for non-French speakers.

  3. 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

tiny trout
#

Okay my bad

ember kernel
#

Good luck anyway

tiny trout
ember kernel
#

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

cyan night
#

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

ember kernel
#

There is indeed an algebrical way to solve this

#

Give me some time to write it on paper

cyan night
#

aight

#

i am giving a and i the maximum values which are 8 and 9 right

cyan night
#

u there quentin

mossy fjord
cyan night
#

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

mossy fjord
cyan night
#

yeah

#

u tried it out yet

mossy fjord
cyan night
#

ok no problem thanks for trying it out

drowsy fog
#

Sorry its a bit blurry, but does anyone know how to solve 1(b)

thorny flicker
#

can help with this

cyan night
#

is that a test

drowsy fog
#

Nope, just an exercise

#

Although my test coming up tomorrow TwT

cyan night
#

@ember kernel wwhats up?

#

got it yet?

#

dang

ember kernel
cyan night
#

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

ember kernel
#

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

cyan night
#

ah

#

yes the solutions

#

so

#

ill just say

#

i did

#

"trial and error"

#

and i got that

#

PRO
BIG BRAIN MY CLUEBERRY FAYGO

ember kernel
#

You don't need to lie for that

cyan night
#

my friends they just copid the solution from the internet

#

but i have explanation

ember kernel
#

Just be honest, write that you couldn't find a proper pattern and that trial and error didn't give you any satisfactory solution

cyan night
#

there really was no proper pattern

#

aight

#

thanks quentin

ember kernel
#

No problemo

cyan night
#

@ember kernel wait are those all of the solutions

cyan night
#

this is bs problem imagine if my teacher doesnt grade this i force her to grade

ember kernel
#

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

cyan night
#

Ah ok

cyan night
#

that is the property of absolute value?

vapid osprey
#

I'm out of ideas on how to start

cyan night
#

do u know what is absolute value

twin sluice
#

is anyone here good in mathematical logic?

calm trail
#

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

lofty arch
#

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

left knoll
#

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

fringe stratus
#

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

polar heron
ember kernel
fringe stratus
north geyser
#

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?

fringe stratus
# north geyser

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 -∞

north geyser
#

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

fringe stratus
#

oh yeah then you were right about the -2 limit 🙂

left knoll
#

Anyone?

polar heron
# left knoll 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.

tawny stratus
#

Any help pls?

cyan night
#

use pascal triangle to expand (a+b)^n

#

i think

#

thats my approach its definitely one of the worst

fleet agate
#

guys do u have a basic math book

#

for the begginers

ember kernel
#

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)

ivory pumice
#

Nais

craggy plume
#

Can someone explain where does the square root of the first x+4 goes?

polar heron
craggy plume
polar heron
meager girder
#

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

ember kernel
# meager girder i have my maths exam on oct 29th /2nd nov it's Pure maths 3 and mechanics 1 (A2)...

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 !

cyan night
#

ye and ask me for help

ember kernel
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Ask anyone* for help ^^

cyan night
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ye

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quentin have u ever gone to amcs yet

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why take so long

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🤔

ember kernel
# fringe stratus Wow good freaking catch, thanks ! Simple curiosity, how'd you arrive to that con...

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

cyan night
#

isnt that peroperty of pascal

ember kernel
#

Tbh I can't remember what this property is precisely

ember kernel
ember kernel
cyan night
#

like the amc8 amc10 amc12

ember kernel
cyan night
#

hmm oke but the competition is worldwide we also do it in asia

ember kernel
#

Oh I had never heard about it.
But tbh, I think it's kinda off topic in this channel

cyan night
#

ok

meager girder
#

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

harsh dragon
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differential equations 😳

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i am taking differential equations right now

meager girder
meager girder
harsh dragon
#

me too

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i gotta review my integrals and derivatives again

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its been two years since i done that stuff

meager girder
#

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

harsh dragon
#

does paper mean "syllabus"

meager girder
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well yes the topics for the specific exam

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in maths i have 2 sub exams , one is pure math also known as calculus and the other exam is Mechanics

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honestly man i'm also lost because i have to self study the syllabus . i don't have school

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anyway thank you alot for the tips, i needed at least some guidance to get my mind straight

harsh dragon
#

the topics in your syllabus

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are you learning all of the topics in you syllabus for the first time

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or are some review

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cuz if u already did pre-calc, then it seems like a pretty standard clauclus course

meager girder
#

yes ive done them before but it was months ago so now they're really vague to me

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here's the syllabus if you guys wanna check it out

proven orchid
#

any help here would be appreciated

fringe timber
#

Is this right and if so why do i extend the 4 with times 2 instead of + 2?

winged coyote
fringe timber
#

But why is that? i dont understand it

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@winged coyote "+2 would not have gave u the same base of two that you need to solve" why?

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cus normaly 2^2 is 4

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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 😄

covert briar
cyan night
#

ok

solid anvil
#

square has all sides equal

covert briar
#

yes

solid anvil
#

ab=ac

covert briar
#

mhm

solid anvil
#

cant we do my way as square has all sides equal?

covert briar
solid anvil
covert briar
#

wait so can u show the process
like what do u find first '
what do u find next and so on

cyan night
#

im confused

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im very confused.

solid anvil
covert briar
cyan night
#

equation of ac is 2x+y-5 = 0 <=> y = 2x-5 => slope of y = 2? meanwhile ac's slope is ad/ac = 1??

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i am confused

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i mean

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-1

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ad/ac = -1

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rise over run not the fraction

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uhh

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anyone

covert briar
#

wait ha

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still tryna figure this out

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also it will be y = 2x+5 not -5

solid anvil
cyan night
#

guys

covert briar
cyan night
#

teh distance from midpoint ac to a,b,c,d is sqrt 20

solid anvil
cyan night
#

slope is sqrt 20

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or 2 sqrt 5

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from midpoint ac to b

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i think i got answer

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a is (2(3+sqrt.10/2,)-1-2(sqrt.10/2))

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b is

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(3+sqrt.10/2,-1+2(sqrt.10/2))

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im just messing around guys

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!!! amogus