#help-36

1 messages · Page 268 of 1

desert mantle
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and how you can replace those to get what you want

grim nebula
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@trail mango its the fibonacci generating function

thin jay
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what

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ohhh

grim nebula
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its possibly clearer if you do x instead of 1/10

thin jay
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i kiiiiinda see that c is constant so summing it and multiplying it should be the same

grim nebula
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,, S(x) = \sum_{n = 0}^\infty F_n x^n

soft zealotBOT
rugged merlin
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So like 1 + 2 + 3 -> 2(1 + 2 +3) = 2*1 + 2*2 + 2*3

thin jay
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okey

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i get that!!!!

rugged merlin
thin jay
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but like

rugged merlin
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So 2(1+2+3) is like the LHS here and 2*1 + 2*2 + 2*3 is like the RHS here

rugged merlin
thin jay
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i dont understand why the person who did the reddid thingy added 2 extra terms shifted by 10x of the same number

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because like

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shouldnt F (to the subscript n) be always the same for the same n?

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and why do the n change later ???

thin jay
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what

rugged merlin
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You can totally reindex that

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Like

thin jay
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regular day at discord ig

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lmao

rugged merlin
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,, \sum_{k=c}^n a_k = \sum_{k=c\0o{-m}}^{n\0o{-m}} a_{k\0b{+m}}

soft zealotBOT
rugged merlin
#

You can do this

thin jay
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i dont immediatly see why

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and i also dont see why after thinking about it XD

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wait

rugged merlin
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😅

thin jay
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is a a function?

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or a set?

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or like

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something else

grim nebula
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,, \sum_{n = 0}^\infty F_{n + 2} = \sum_{n = 2}^\infty F_n

soft zealotBOT
grim nebula
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heres an example

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theyre both F_2 + F_3 + F_4 + ...

thin jay
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ohhhhh

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i see

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kinda

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why does the upper bound (infinine or k) need to be subtracter by 2?

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in this case

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i see how i can move the +2 to the bottom

grim nebula
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in your case it doesn't matter because the sum is infinite

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,, \sum_{n = 0}^{100} F_{n + 2} = \sum_{n = 2}^{102} F_n

rugged merlin
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Cuz if you dont you'd be adding more terms than originally, in the finite case

grim nebula
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theyre both F_2 + F_3 + ... + F_102

thin jay
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ohhhhhhhhhhhhhhhhhhh

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i get it now

soft zealotBOT
thin jay
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its like if you opened a window and you just shifted it

grim nebula
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,align S(x) & = \sum_{n = 0}^\infty F_n x^n \
\sum_{n = 0}^\infty F_{n + 2} x^n & = \sum_{n = 0}^\infty (F_{n + 1} + F_n) x^n \
& = \sum_{n = 0}^\infty F_{n + 1} x^n + \sum_{n = 0}^\infty F_n x^n \
\sum_{n = 0}^\infty \f {F_{n + 2} x^{n + 2}} {x^2} & = \sum_{n = 0}^\infty \f {F_{n + 1} x^{n + 1}} x + \sum_{n = 0}^\infty F_n x^n \
\sum_{n = 2}^\infty \f {F_n x^n} {x^2} & = \sum_{n = 1}^\infty \f {F_n x^n} x + \sum_{n = 0}^\infty F_n x^n \
\f {\ds\sum_{n = 0}^\infty F_n x^n - F_0 - F_1 x} {x^2} & = \f {\ds\sum_{n = 0}^\infty F_n x^n - F_0} x + \sum_{n = 0}^\infty F_n x^n \
\f {S(x) - 1 - x} {x^2} & = \f {S(x) - 1} x + S(x)

thin jay
grim nebula
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wdym

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the second line is just a true statement

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F_n+2 = F_n+1 + F_n

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so the LHS = the RHS

thin jay
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i suppose thats only true for the fib sequence because its defined as F_n = F_n-1 + F_n-2 right?

soft zealotBOT
thin jay
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okey

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but how do you expand it to two infinite sums?

grim nebula
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sum (a+b) = sum a + sum b

rugged merlin
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I think you just need to freshen up on your sum manipulation

thin jay
grim nebula
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blud copied the google metadata

rugged merlin
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Just read that

thin jay
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am i supposed to close the help channel now? 😅

rugged merlin
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If you want

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You can keep it open if your confusion is still unresolved though

thin jay
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ima read and understand the sum manipulation thing first, and if i still dont get it ill open another one :p

thin jay
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thanks!!!!!

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.close

final saddleBOT
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Channel closed

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Use .reopen if this was a mistake.

rugged merlin
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Np

final saddleBOT
#
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grizzled socket
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In the cartesian plan graduated in meters, we illustrated the view of the top of the possible landing zone of a space probe. The vertices of this zone trapezoidal area correspond to the intersection points of a circle with 10 m of diameter and of the curve associated with a absolute value functon in which the equation is y = 3|x| - 9. Determine the area of the possible landing zone

grizzled socket
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Idk how to start this

halcyon ether
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Maybe by making a rough sketch?

night raft
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Try assume the circle is centred at (0,0) and make an equation out of it

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then find the intersection points of the circle and the absolute value function

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but yeah a rough sketch is a good start

grizzled socket
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It's been 4months since i did this notion so i kinda forgot

night raft
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the equation for a circle?

grizzled socket
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The absolute value function

night raft
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do you know the definition of the absolute value function at least?

grizzled socket
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Cant be negative

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r^2 = x^2 + y^2

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25 = x^2 + y^2

night raft
grizzled socket
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?

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Nvm got it

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.close

final saddleBOT
#
Channel closed

Closed by @grizzled socket

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
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ivory quartz
#

Question 4

When you roll two 6-sided standard dice, which of the following is the most likely to occur?

A. The sum of the two rolled numbers is a multiple of 5.
B. The sum of the two rolled numbers is a multiple of 3.
C. The sum of the two rolled numbers is a prime number.
D. The sum of the two rolled numbers is a multiple of 4.
E. The sum of the two rolled numbers is greater than 8.

I drew a sample space diagram to find every P(A) and just picked the one with the biggest x/36 which is C..

But I think drawing an entire sample space diagram in a fast-paced competition is rather tedious... Just wanted to know if there's a quicker way of solving this

halcyon ether
onyx peak
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if you're allowed to do this kind of heuristics, it takes like 30 secs

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it's also important to know that the most probable sum is 7 and then the probability decreases linearly as you move further from 7

ivory quartz
halcyon ether
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Holy

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Oh wait it's the same thing haha, but your is just tedious

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Hang on

onyx peak
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you dont really need to write all the 5,3 stuff

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you only need the sums

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and if you look at it, the sums are same at diagonals

halcyon ether
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Okay ig I don't have to draw a clearer one then

halcyon ether
onyx peak
# ivory quartz smth like dis

all you need is just this, you dont even need to continue after the 3 dots - spot the pattern and move on, no need to write it all out

All you need is to know how frequent each sum is
2 -> 1
3 -> 2
4 -> 3
...
7 -> 6
8 -> 5
...
12 -> 1
done

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if you're in a competition, dont waste time by writing down all the bits that you can easily complete in your head

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if its a very mechanical, obvious and predictable thing, thats a good sign that you probably dont need to write it all out

trail mango
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amen

onyx peak
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awomen layla

trail mango
ivory quartz
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thx!

#

.close

final saddleBOT
#
Channel closed

Closed by @ivory quartz

Use .reopen if this was a mistake.

final saddleBOT
#
Available help channel!

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Show your work, and if possible, explain where you are stuck.
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warm stream
final saddleBOT
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Please don't occupy multiple help channels.

next thorn
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did you write those numbers on the figure?

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the 4 and the 4

south dirge
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hes occupied 2 help channels by mitsk

next thorn
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i see

true hinge
next thorn
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and i also now see that you're supposed to count the squares

halcyon ether
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one of you shoould close it since it's still open

south dirge
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or mods

halcyon ether
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Then tell them

south dirge
next thorn
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.close

final saddleBOT
#
Channel closed

Closed by @next thorn

Use .reopen if this was a mistake.

next thorn
halcyon ether
true hinge
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Alright.

south dirge
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-# wait helpful can close?

halcyon ether
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Yes

south dirge
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-# i had no idea

next thorn
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lmao

halcyon ether
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Lmao

next thorn
#

@south dirge

south dirge
final saddleBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
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stable dew
#

what is the domain of

f(x)=xsqr/(1-xsqr)

final saddleBOT
rugged merlin
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What is the domain of xsqr

stable dew
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wait nvm

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i got it

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i got one end point wrong...

onyx peak
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Whats xsqr btw

stable dew
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x^2

onyx peak
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x^2?

stable dew
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yeah

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oh yeah f:R-{-1,1}-->A

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we needa find A

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i took f(x)=y

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made quadratic

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and took D>=0

south dirge
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was there a need for all that?

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whtd you get the range as anyways

stable dew
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hmm?

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R-[1,0]

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oh wait it cant be zero caus of our domain

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wait a sec

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bruh i acdentally wrote doamin instead of range

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:p

onyx peak
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Even as the domain it looks wrong

stable dew
south dirge
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x can be 2 also

onyx peak
stable dew
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i wrote domain by mistake

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:/

onyx peak
#

Its not the range either

south dirge
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for domain, the only restriciting factor you need to see is that denomitr becomes 0

stable dew
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i didnt find it

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i needed to find A

onyx peak
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But it looks more like the range. One of your endpoints is wrong and you should also think about the brackets ([

south dirge
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Its fine lets do using y

stable dew
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it can be 0 for x=0

south dirge
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can you send your working so we can check?

stable dew
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wait a sec

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my camera sucks

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(on laptop)

south dirge
#

Bhai tu jee ka hai🥀

south dirge
# stable dew

sun na all this is fine but tune end mein kya kiya

stable dew
#

yeah bruh

just started 12th🥀

south dirge
#

y(y+1)>=0 tak theek hai

south dirge
stable dew
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dang

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my math sucks :/

south dirge
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Tune jo likha wo exact opposite hai

stable dew
#

huh?

south dirge
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the range ke liye tune jo +-+ number line wala banay

stable dew
#

yeah

south dirge
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usse toh -1,0 ke beech mein nahinho skta na

stable dew
#

yeah

south dirge
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wahan par - ho rha hai

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and you need it to be +ve

stable dew
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that why i excluded (1,0)

south dirge
stable dew
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there a "/" after R

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it mean i excluded

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i put wrong bracket tho....

south dirge
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bro i thought you meant R is 1,0

south dirge
stable dew
south dirge
#

Acha phir toh sahi hai

stable dew
south dirge
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range is -inf,-1) U (0,inf)

stable dew
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caus from quadratic it cant be equal to 0

south dirge
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thats what u mean to say na

stable dew
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look at orginal f(x) and check if it can equal out critical points

south dirge
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haan sry i meant ]

stable dew
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kk no prob

south dirge
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wo square bracket nahi mil rha tha

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😭

stable dew
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xD

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phone?

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or laptop

south dirge
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phone

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its lenovo ka

stable dew
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yeah

south dirge
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2015 model🥀

stable dew
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idk where sqr bracket is either

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on phone

south dirge
stable dew
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bro's cooked

really had to type "square bracket" in google and copy

south dirge
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sed times

stable dew
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@drowsy epoch wassup

drowsy epoch
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hi

stable dew
drowsy epoch
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good n u

south dirge
stable dew
stable dew
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bru im think i just write every step now

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that prolly the only way ima save myself

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well ima go do sum more mistakes

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cya later

#

.close

final saddleBOT
#
Channel closed

Closed by @stable dew

Use .reopen if this was a mistake.

final saddleBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

mortal island
#

Getting back into it this morning, help me get through this?

night raft
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do you know log laws?

mortal island
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Sort of

night raft
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which one can you apply here

mortal island
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Uhhhhhh

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Could you show me the laws?

onyx peak
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note that they all work in reverse too

mortal island
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Ok

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Product rule?

night raft
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yep

mortal island
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Right…

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Do I need to get rid of the -1 and -5?

night raft
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no keep them there

mortal island
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Do I foil it or just combine as normal?

night raft
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wdym?

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like expand it after you applied product rule

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then yeah you can do that, keep them all as one bracket though

mortal island
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Uhh…..

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Idk what that means

night raft
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like after you do $\log_5 (3x-1)(4x-5)$

mortal island
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So foil it????

soft zealotBOT
night raft
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yes expand it

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don't know what foil is

severe canyon
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$\log_5{[(3x-1)(4x-5)]}$

mortal island
soft zealotBOT
#

Alberto Z.

mortal island
#

I don’t remember what it means

severe canyon
mortal island
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But that’s how my teachers have always referred to it

severe canyon
mortal island
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I think that’s OSHA

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Food safety

night raft
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so yeah once you've done that, you can then apply this rule $\log_{a}b = x$ is the same as $a^x = b$

soft zealotBOT
night raft
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i keep forgetting my \ monkey

mortal island
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Uhhh…..

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Right so how do I apply that- here

night raft
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12x^2 - 15x - 4x + 5 = 5^0

mortal island
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Wait…why is it 5^0?

severe canyon
soft zealotBOT
#

Alberto Z.

solar glade
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Use the inverse of log_5

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to remove the log_5

mortal island
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Ok-

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So now I have LHS = 1

severe canyon
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Or simply do 5^ both sides

mortal island
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Ok-

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Subtract 5 on both sides to get rid of that-

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Square root to get rid of the square…?

modest badge
mortal island
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Can I square root a negative….

modest badge
#

logarithms get really funky when you have roots of negatives in them

mortal island
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I gotta get rid of this square somehow

night raft
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but I don't think the solution contains it

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oh

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it says no solution in one the options

mortal island
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Oh is it just no solution?

night raft
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yeah you can pick that

mortal island
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Said that was wrong

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One more attempt

modest badge
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i think you're doing the quadratic equation wrong

mortal island
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It’s not a quadratic equation-

night raft
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they mean the 12x^2 - 15x - 4x + 5 = 1 part

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and solving it

mortal island
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Oh

night raft
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,w solve 12x^2 - 15x - 4x + 5 = 1

night raft
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yeah so you should be getting real solutions

mortal island
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I figured

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But I don’t understand…how

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Idk what I’m doing wrong

night raft
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could you show your working out?

mortal island
night raft
soft zealotBOT
mortal island
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Ignore my horrid handwriting

modest badge
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in the second to last step, you should add 5 to both sides to cancel the -5

mortal island
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But the 5 isn’t negative

modest badge
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ur right

mortal island
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So adding would only make the 5 10

solar glade
#

Milo

night raft
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do you know how to factor a quadratic?

solar glade
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That's not how you are supposed to do

night raft
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12x^2 - 19x + 4 is factorable

solar glade
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You have to let 0 in one side, not -4

mortal island
solar glade
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eitherway you won't be able to factor properly

modest badge
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actually

mortal island
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But I still wouldn’t have 0

solar glade
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You better respect people here

mortal island
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Because I have 5^0

mortal island
solar glade
mortal island
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Ok…?

solar glade
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so left side = 0

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what is left side?

modest badge
mortal island
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12x^2 -19x +4

solar glade
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now factor that

mortal island
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You can’t

solar glade
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over reals

mortal island
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19 is a prime number

solar glade
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you can

mortal island
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You can’t pull anything out of 19 besides 1 and 19

solar glade
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u can factor

mortal island
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????

modest badge
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you have to use the quadratic formula to find the solutions

night raft
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yeah you can use quadratic formula but its slower

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when it is factorable

mortal island
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None of this is in the example problem….

modest badge
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can you share that one?

mortal island
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Sure

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It’s rly long tho so it’ll be multiple pics

solar glade
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Write -19x as -3x -16x

mortal island
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What?????

solar glade
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you will be able to factor like that easily

mortal island
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????????

solar glade
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12x^2 -3x -16x + 4

mortal island
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You’re just confusing me

night raft
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do you generally know how to factor?

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a quadratic

mortal island
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You can’t factor 4 by 3 or 3 by 4

solar glade
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yes i can

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you mean "you" don't know how to

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you have to pay attention

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instead of saying you can't

mortal island
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I am bro tf

solar glade
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when we are telling you that you indeed can

night raft
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If you don't know how to then I'd advise you learn it or listen to arkimond explaining it

mortal island
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I’m trying to but bro is confusing me

modest badge
mortal island
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There’s not a single thing you can pull out of all 4 of those numbers

solar glade
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i literally only said rewrite -19x as -3x -16x

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i don't think it's impossible to follow this step

mortal island
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Ykw…I’m gonna put in a bs answer for this one and we can start over on a new problem

solar glade
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i can't help whoever doesn't want help

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good luck

modest badge
#

factoring in this case is a little more complicated than just splitting a number into its multiples

mortal island
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But I’m lost on the step we’re on

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So I’m saying- let’s start over on a new problem

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From the beginning

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Also the answer wolfram alpha gave was wrong- just sayin

modest badge
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it means splitting the equation into chunks that can be rewritten

mortal island
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Right new problem

modest badge
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we start the same as last time, combine the logarithms using the product rule

mortal island
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Ok

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That got me log_5 (12x^2 + 21x + 8x +14) which I then condensed into log_5 (12x^2 + 29x +14)

modest badge
#

correct. once that is done, you can write 5^LHS = 5^RHS, this will cancel out the logarithm

mortal island
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Right

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So 12x^2 + 29x + 14 = 25

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do we agree

modest badge
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we agree

mortal island
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Ok now what

modest badge
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now you subtract 25 from both sides, you want an expression that is = 0

mortal island
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Ok

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So 12x^2 + 29x -11 = 0

modest badge
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yes

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now the most meticulous way is to use the quadratic formula to solve for x

mortal island
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Ok- I don’t love that-

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What’s the other way-

modest badge
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if you have some intuition with factoring quadratic trinomials into a product of binomials, you can do that

mortal island
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….i don’t-

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I’m not a very “math” person

modest badge
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then the quadratic formula is the best way

mortal island
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Ok

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Does it matter which value is which-

modest badge
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it's arbitrary, but just remember them once you choose which is which

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or wait+

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what values do you mean?

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the a, b, c?

mortal island
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For the quadratic formula…

modest badge
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it does matter

mortal island
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Oh ok

modest badge
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in this case, a = 12, b = 29, c = -11

mortal island
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That’s why I was gonna do anyways

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Do I need to keep the x’s and such- or just the numeric value

modest badge
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just the numeric value

mortal island
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Ok

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Ok

modest badge
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you got the values?

mortal island
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Yes

modest badge
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ok, now you should simplify the expression

mortal island
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Ok-

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Wait should the 11 be negative?

modest badge
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yes

mortal island
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Ok just making sure

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Uhhhhh

modest badge
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all correct

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honestly i don't think there's an issue with using a calculator for that root

mortal island
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What do I do w the -29…and….that fraction is really ugly

modest badge
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unless calculators are completely forbidden

mortal island
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Root first or division first-

modest badge
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root first

mortal island
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I’m not sure but I also don’t think that’s how they were taught to do it

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I missed this whole group of lessons completely

#

The calculators were allowed to use…I’m not sure they can do this-

modest badge
#

can your calculators take the square root is a number?

#

once you do that, the fraction becomes much easier

mortal island
#

Yeah

#

I got it to -29 +/- 37/24

modest badge
#

yes, now you do the addition / subtraction first, then the division

#

you'll get two different numbers

mortal island
#

Uhhh ok-

#

I can’t get my answer in fraction form 🥲

modest badge
#

why not?

mortal island
#

My phone calculator won’t put it in fraction form

#

I’m like barely functioning rn I can’t…remember what it is

modest badge
#

then simplify them manually on paper

mortal island
#

🥲

#

I’m not 100% sure I can do that-

#

At the current moment

modest badge
#

ok, i can help you with that. you'll get -66/24 and 8/24

mortal island
#

Yes

modest badge
#

which, whn simplified, give -11/4 and 1/3

mortal island
#

Ok-

#

So is that….the answer?

#

But it can only be positive right?

modest badge
modest badge
mortal island
#

So….only 1/3?

modest badge
# mortal island

not necessarily, you need to try both in the original expression

#

just for thoroughness' sake

mortal island
#

(I have 2 attempts I’m not rly gonna risk it if it’s wrong it’s wrong I pick no solution)

#

(As long as the assignment is done)

#

Alright new problem- slightly more complex

modest badge
#

same as last time, product rule to combine logarithms

#

2^LHS = 2^0 = 1

mortal island
#

But….its not added?

#

It’s subtracted

modest badge
#

my bad, i wrote too hastily

mortal island
#

Ur good

modest badge
#

use the quotient rule in that case

mortal island
#

So literally just….. log_2 (2x^2 +2 / 3x +1)

modest badge
#

yes

mortal island
#

Right…what’s the next step here?

modest badge
#

and now, 2^LHS = 2^RHS

#

so, (2x^2 + 2)/(3x + 1) = 1

mortal island
#

Yeah

#

Subtract the RHS 1 on both sides…?

modest badge
#

no, there's an easier way

#

multiply both sides my 3x+1 to cancel out the denominator of the LHS

#

you get 2x^2 + 2 = 3x + 1

mortal island
#

Wouldn’t you have to foil the bottom tho-

modest badge
#

you're not multiplying top and bottom by 3x+1

#

you're multiplying only the top

mortal island
#

I know

#

But how does the bottom cancel…

modest badge
#

(3x + 1) / (3x + 1) = 1

mortal island
#

Oh

#

Ok

#

Subtract the RHS to get zero?

modest badge
#

yes

severe canyon
#

You definitely need to brush up the basics. This has nothing to do with log stuff.
Also you need to be very confident in solving second degree equations (aka quadratics)

modest badge
#

bro is tired, cut him some slack

mortal island
#

I was up until 4 am last night doing this homework that’s still not finished

modest badge
#

so, 2x^2 - 3x + 1 = 0

mortal island
#

Yes

modest badge
#

now, you can use the quadratic formula again, but this expression is smaller than last time, so i think we can try factoring it rn

modest badge
#

so, we're looking for an expression of the form: (mx + p) * (nx + q) = ax^2 + bx + c

#

in this case, a = 2, b = -3, c = 1

mortal island
#

Ok-

#

🫩

severe canyon
#

<@&268886789983436800>

mortal island
#

<@&268886789983436800>

modest badge
#

<@&268886789983436800>

mortal island
#

Twin

modest badge
#

let's proceed

mortal island
#

Where does (mx + p) * (nx + q) come from?

#

I’ve never heard of that

modest badge
#

now, if we do FOIL of RHS, we get (mn)x^2 + (mq + np)x + pq

modest badge
mortal island
#

Alright I guess that makes sense

#

So are we splitting the 2x^2?

modest badge
#

yes

mortal island
#

Ok

modest badge
#

now, we match the terms on the RHS and LHS according to the degree of x they mulitply

mortal island
#

So is it….. (2x [other part]) * (2x [other part])

severe canyon
#

Nope, otherwise you would get 4x²

modest badge
#

no, in this case we split it into 2 and 1

mortal island
#

Ohhhh

modest badge
#

(mn)x^2 + (mq + np)x + pq = 2x^2 - 3x + 1

#

so, the x^2 has mn and 2, so mn = 2

mortal island
severe canyon
#

It is quadratic equation basics blobcry blobcry you should be very familiar with that

mortal island
#

It’s a joke 🥲

modest badge
#

we multiplied the LHS, and have the expression we're trying to factor on the RHS

#

now, the x^2 term has mn in the LHS and 2 in the RHS, so mn = 2

mortal island
#

Yes

modest badge
#

so, we write m in terms of n, m = 2/n

mortal island
#

….idk if I follow

modest badge
#

ok, i'll continue for now and come back to this in a bit

#

we have mn = 2

mortal island
#

Right

modest badge
#

similarly, the LHS term that has no x is pq, on the RHS it's 1

#

so pq = 1

mortal island
#

Right

modest badge
#

now, for the term with x, mq + np = -3

mortal island
#

So…should we break the -3 up into 2 terms?

modest badge
#

let's do something else first

mortal island
#

Ok ok

modest badge
#

let's focus first on mn = 2 and pq = 1

mortal island
#

Alright

#

I want you to finish explaining but I’m not sure that I love this method

modest badge
#

yeah to be honest, in usually just stick to the quadratic formula

#

once you use it a lot you learn to love it like family

mortal island
#

Yeah it’s kinda muscle memory

modest badge
#

but you mentioned you don't think your class did it that way, so i'm explaining the other approach

mortal island
#

I like clean cut concise- can use it over and over again and nothing changes

mortal island
#

She might’ve let them break out the good calculators for it

#

I know they said they got to use them at some point-

modest badge
#

for now, we know that mn = 2

mortal island
#

Yes

modest badge
#

let us split the 2 into 1*2

#

and say that m = 1, n = 2

#

we're just making an educated guess and seeing if it gets us somewhere

mortal island
#

Alright

#

Well that’s…about all you can break it into

#

2 is a prime number

modest badge
#

but we also know that pq = 1

#

so we'e looking for two numbers that multiplied give us 1, but when q + 2p = -3

mortal island
#

Right…

#

So we’d have to get uh….-5?

modest badge
#

no

mortal island
#

Oh

#

Well the only way to get 1 is 1•1 or -1•-1

modest badge
#

exactly

#

(actually, you can get an infinity of values like 5 and 1/5, but in this case the answer IS -1 and -1)

mortal island
#

Ohhhh

modest badge
#

so, m = 1, n = 2, p = -1, q = -1

modest badge
#

2x^2 - 3x + 1 = (x - 1) * (2x - 1)

#

that is how you factorize it

mortal island
#

🫩

#

Right so…..

#

How does that get me anywhere

modest badge
#

so, (x - 1) * (2x - 1) = 0

#

now, we did all this because, if you are multiplying 2 values and the result is 0

#

that means that either 1 or both is 0 too

mortal island
#

Right….

modest badge
#

so we get two possibilities, x - 1 = 0

#

and 2x - 1 = 0

#

so now we solve for x in each of the cases

mortal island
#

So x=1 and x= 1/2

modest badge
#

ye

#

thoseare your values of x

mortal island
#

It took the answers 🙏

modest badge
# mortal island

now you put them into the logarithm and confirm the inside is positiv

#

but since rn you're just adding positive numbers, it works as is

mortal island
#

Ok ok I’m gonna attempt a problem- with not as much guidance

modest badge
#

cheers

mortal island
#

Look good so far?

#

Wait is the 19 out in front of the quadratic positive or negative

#

Because it’s negative in the problem but if you make a negative…negative- it becomes positive

#

does it matter either way?

final saddleBOT
#

@mortal island Has your question been resolved?

mortal island
#

THESE ANSWERS CAN ONLY BE POSITIVE RIGHT???????

modest badge
#

sorry, i went to the restroom and forgot i was here

modest badge
mortal island
#

Ok ok ok

final saddleBOT
#

@mortal island Has your question been resolved?

#
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tender nacelle
#

Howd i get such a big ln thingy. It should be 5/12

final saddleBOT
#

@tender nacelle Has your question been resolved?

tender nacelle
#

<@&286206848099549185>

#

.close

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quick delta
#

o

final saddleBOT
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late gazelle
#

how do you go about graphing letters using functions ?

lofty goblet
#

what does this mean

whole halo
#

go to the desmos unofficial discord for Big Suggestions

lofty goblet
#

do you mean actual letters of the alphabet

late gazelle
whole halo
#

are you using desmos to graph these shapes?

late gazelle
#

yea

whole halo
lofty goblet
#

you could probably do them with the most basic equations

#

like linears and quadratics and maybe circle for letter O

late gazelle
#

what about more interesting ones like the greek alphabet

#

because those are more irregular

#

would i import a picture of it in desmos, and then trial and error until i can "cover" it

whole halo
#

its just a differently shaped letter, you dont need to overlay a reference picture

#

you can just bring one up then refer to it

#

I imagine youre not going for anything hard or fancy, just lines and circles maybe

#

try making sure you can draw lines and circles that start/end where you want them

late gazelle
#

mhm ty

#

.close

final saddleBOT
#
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whole halo
#

np

final saddleBOT
#
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dim gyro
#

When doing Sinx = sqrt(1-cos^2x)

final saddleBOT
dim gyro
#

Do you always do a positive square root?

#

Since it’s meant to be plus or minus right, how do you decide?

sonic crystal
formal trail
#

square root is always positive

dim gyro
#

I’m just asking generally

#

Since it’s come up a few times

formal trail
#

a better way to phrase it imo would be to say |sin(x)| = sqrt(1-cos^2(x))

#

and then determine the sign based on quadrant

dim gyro
#

So it depends on the angle of x?

formal trail
#

yes

dim gyro
#

So it’s not always positive then?

formal trail
#

sin(x) can be either positive or negative depending on what x is, yes

#

the most intuitive way imo is to draw the angle on the unit circle and see if it ends up with a positive or negative y-coordinate

dim gyro
#

Oh you mean like -sinx = sqrt ect
So you multply both sides by -1

#

But the actual root is always taken to be positive

#

Depending on quadrant

formal trail
#

the notation of square root is always used to mean positive

#

you can do sin(x) = +sqrt(...) or sin(x) = -sqrt(...) as appropriate

dim gyro
#

So for example

#

If x was inbetween 90 and 180

#

Sin would equal the negative sqrt ect

#

Since sin is plus in that quadrant and cos is negative?

formal trail
#

you said that sin is positive, so why would you add a - sign?

dim gyro
#

Because cos is negative at that range no?

#

Or is it just dependent on sin?

#

So only 180 to 360

formal trail
#

we're saying sin(x) = ... so the thing on the right side had better match the sign of sin

dim gyro
#

Ahh ok so if it’s in the lower half of the circle

#

Then you say sinx = -sqrt ect

formal trail
#

yes

dim gyro
#

Ahh thanks for the clear up

#

That had me confused

#

.close

final saddleBOT
#
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final saddleBOT
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crystal lion
#

just wanted to make sure that i got this right:
As t tends to infinity:
arctan(t) tends to pi/2
arctan(-t) tends to -pi/2
arctan(t^-1) tends to 0
?

crystal lion
#

thanks and does arctan(t^2) tend to pi/2 as well?

rugged merlin
crystal lion
#

kk thanksss!

rugged merlin
#

any arctan(t^n), n > 0, t -> infinity will be like that

crystal lion
#

.close

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nimble basin
#

9^x - 4 • 3^x + 3 = 0

final saddleBOT
quasi rapids
#

OH wait this doenst need that

#

what am isaying

mossy chasm
#

lol

drifting idol
quasi rapids
nimble basin
#

Then factorization?

timber leaf
#

Overthinking

timber leaf
nimble basin
#

Two roots

quasi rapids
timber leaf
timber leaf
nimble basin
#

I always stuck at q like these

timber leaf
#

If 3^x = 2 roots, can you use logs?

#

Do more questions and you get used to it

nimble basin
timber leaf
#

I see

#

Find 2 roots first

#

Then let see what can we do

nimble basin
#

Where can I find more q like these

timber leaf
#

Textbooks

nimble basin
final saddleBOT
#
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mossy chasm
#

again, no idea what to even do, but its probably cauchy schwarz

uneven idol
#

ezpp

night raft
#

It probably is cauchy schwarz

mossy chasm
#

nvm might have accidentally found the solution after tweaking around even more

#

i love titu

#

should be M>155 right?

final saddleBOT
#

@mossy chasm Has your question been resolved?

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lime crest
#

220 positive integers which sum to 400 are arranged in a circle. Prove that there exists a string of integers along the circle which sum to $200$

soft zealotBOT
#

Copter

lime crest
#

i have no idea how to think of this problem

coarse monolith
#

same.

south dirge
lime crest
coarse monolith
coarse monolith
south dirge
#

As in repeated?

lime crest
#

if they were distinct then the sum would be way more than 400

south dirge
quasi rapids
sturdy flax
#

<@&268886789983436800>

quasi rapids
#

why are there so many like weird server invites nowadays

#

speak of the devil

south dirge
#

<@&268886789983436800>

lime crest
quasi rapids
# lime crest yeah but im not sure how

suppose x1, x2, ... x220 is our sequence of integers
let S1 = x1
S2 = x1 + x2
S3 = x1 + x2 + x3 and so on

||since xn is a positive integer, the sequence of sums is strictly increasing 1 <= S1 < S2 < ... < S220 = 400||

find the number of two sums that differ by exactly 200
as such you can just pigeonhole it

lime crest
#

hm

#

im kinda stupid

#

i get what youre trying to do tho

#

im just not suee how pigeonhole would work

quasi rapids
#

no its ok, you should find that there are exactly ||200|| pairs and since you have 220 sums and each of these sums must belong to one of the ||200|| pairs we found, this guarantees one pair must contain two of our sums

let the two sums in the same pair be Sm and Sn, st Sm - Sn = 200, can you rewrite Sm in terms of Sn and a bunch of other numbers?

lime crest
#

i suck at combi aaaa

quasi rapids
quasi rapids
#

if you can rewrite Sm in terms of Sn and a bunch of other numbers and the other numbers are integer then we find the difference is exactly 200 which completes the proof

quasi rapids
severe verge
#

you have 220 numbers in that sum sequence which means there are at least 2 numbers in that sequence with the same remainder when divided by 200

lime crest
#

oh right that makes more sense

severe verge
#

and so their difference is divisible by 200

lime crest
#

since theyre distinct it must be = 200 since its bounded by 400

severe verge
#

i think you can finish from here

lime crest
quasi rapids
soft zealotBOT
quasi rapids
#

realised the spoiler doesnt do much

#

skull

severe verge
#

lol

lime crest
quasi rapids
#

<@&268886789983436800>

severe verge
#

these bots

quasi rapids
lime crest
#

ohh

quasi rapids
lime crest
#

yeye i see

#

thanks!

#

.close

final saddleBOT
#
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north bison
#

i have an exam for a scholarship tomorrow arguably my most important exam soo far and i suck at math like as u can see in this photo i dont know anything from these questions.

cyan sandal
#

can you translate the questions

north bison
#

theyre on english too

#

english turkish slavic and albanian

cyan sandal
#

oh nevermind i didnt see them

#

which questiona re you stuck on

north bison
#

All of them really

#

out of the 25 math questions i got 20 wrong

cyan sandal
#

ok, can you take a clearer photo of the first question

#

i cant really see it

north bison
#

sure thing

#

these questions are probally easy

tired remnant
#

i need help with operatory combined

north bison
#

but im really bad at math cuz i dont pay attention

cyan sandal
#

ok have you started, or are you stuck on any particular step

wintry pier
north bison
tired remnant
#

someone here speak spanish

north bison
#

but i got it wrong and i dont rrally understand it

cyan sandal
#

but 13 is also fine

north bison
cyan sandal
#

you can easily divide the fractions and find the sum

north bison
#

so like -2,256÷22,56=-0.1

cyan sandal
#

yes

north bison
#

+10-1

#

2*

#

thats 19.9

#

not 2.3

#

And the correct answer is 2.3

#

sorry its 7.9

cyan sandal
#

ok so

#

the first fracion equates to -0.1

#

second one is 10

#

-0.1 + 10 = 9.9

#

1 / 0.5 is the same as 1 * (2/1)

#

so 2

#

9.9-2 is 7.9

north bison
#

hm

#

Okay i understand the 13th thanks that wasnt hard

#

what about the one above it

#

12th

#

how does that work idk even how to start

cyan sandal
#

so you want to find the shaded region, which is a quarter of a circle cut out of a triangle

#

can you see that?

north bison
cyan sandal
#

like do you know what imean

north bison
#

the letters?

cyan sandal
#

no , the diagram

north bison
#

Its 6cm

#

the radius

cyan sandal
#

yes, can you see that its 1/4 of a circle, cut out of a triangle

north bison
#

yea

cyan sandal
#

alright, so to find the shaded region you can find the area of the triangle and subtract the area of the arc

cyan sandal
#

the sector of the circle

north bison
#

ok

#

and what about the letters

#

can they help me smh

cyan sandal
#

you can ignore the letters honestly

north bison
#

Ok

cyan sandal
#

the formula for the area of a triangle is 1/2 * b * h

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where b is 12, because 6+6, and the height is 6 (given)

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1/2 * 12 * 6 = 36

north bison
#

uh.

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the answer is 9

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not 12

cyan sandal
#

yes i know thats not the final answer

north bison
#

pi=3

cyan sandal
#

thats the area of the triangle

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the area of a circle is pi * r ^2

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if given r is 6, r^2 is 36, times pi which is 3 (given)

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108 is the area of the circle, but since we only have 1/4 of it, we can times it by 1/4

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, which is 27

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36 - 27 = 9

north bison
#

wow

proper dagger
#

might wanna at least have the helpee do some of the calculation and reasoning themselves next time

north bison
#

i will understand both ways

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anyways

proper dagger
#

no, that's for the helper, not you.

north bison
#

yea ik

cyan sandal
#

so do you understand how i got the answer

north bison
cyan sandal
#

alright next question

north bison
#

14

cyan sandal
#

so do you knwo first of all what the mean is

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of a sequence

north bison
#

Tbf not really

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is it like a variable

cyan sandal
#

alright thats fine, its the average of a sequence

north bison
#

value

north bison
#

Okay

cyan sandal
#

so say i have a sequence with 1 and 3, the average would be 2

north bison
cyan sandal
#

the formula is the sum of the terms in the sequence, divided by the number of terms there are

#

so in my example it would be 1+3 / 2, which is 2

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we can apply that to this

north bison
#

yea

#

Soo

cyan sandal
#

(x + 3 + 17 + 27 + 23 + 29)/6 = 19

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do you see how i set it up

north bison
#

where do u find the /6

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tho

cyan sandal
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because there are 6 terms in the sequence

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so x is a term, 3 is one, 17 is also one e.t.c

north bison
#

Ohh yes

cyan sandal
north bison
#

89÷6

cyan sandal
north bison
#

89÷5?

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cuz we seperate the x

cyan sandal
#

not quite, so you want to get rid of the fraction first

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do you see how you can do that

north bison
#

no

cyan sandal
#

so if you ahve a fraction and yiu want to get rid of it, you can times both sides of the equation by the denominator

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it works because you're doing the same thing to either side, so no change occurs

north bison
#

for example?

cyan sandal
#

in this case you would get x + 3 + 17 + 23 + 27 + 29 = 19*6

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because 1/x * x is 1 because x/x is 1

north bison
#

okay

cyan sandal
#

so try to add the numbers on the left side and multiply on the right

north bison
cyan sandal
#

ill teach you a trick with this one

north bison
cyan sandal
#

you can group them in 2 and add the sums

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so 17 + 3

north bison
#

20 40 29

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and uh

cyan sandal
#

yeah and add them up

north bison
#

89

cyan sandal
#

but wait

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23 + 27

north bison
#

50

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mb

cyan sandal
#

yes

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so 99

north bison
#

99

#

yea

cyan sandal
#

19 * 6 is basically equals to 20 * 6 - 6

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so 120 - 6 is

north bison
#

114

cyan sandal
#

yes

north bison
#

so u need 15

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in order to achieve it

cyan sandal
#

so the equaton is x + 99 = 114

north bison
#

Amazing

cyan sandal
#

well done

north bison
#

i understood this one too yay

cyan sandal
#

last one

north bison
#

i have a feeling 15 is embarrasingly easy

cyan sandal
#

so let the "number" be x

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youre given x/2 + 2x/3 = 21

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what would be your first approach

north bison
#

umm

cyan sandal
#

so your goal is to add the fractions

north bison
#

3x/5?

cyan sandal
#

no, with addition you need a common denominator

north bison
#

6

cyan sandal
#

yes, and to get x/2 to something/6, what would you do

north bison
#

Idk add up x and 2

cyan sandal
#

ok so to get that to 6, you can multiply the denominator by what

north bison
#

2?

cyan sandal
#

2 * what = 6

north bison
#

6*2?

cyan sandal
#

erm

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so 2 times what number is equal to 6

north bison
cyan sandal
#

in other words what is 6 divided by 2

north bison
#

also just one more clarification

cyan sandal
#

yep