#help-23

1 messages · Page 384 of 1

indigo scaffold
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1

normal moss
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doesn't look like it

indigo scaffold
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a = 30

normal moss
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👍

indigo scaffold
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we cant do that for 19,2 = a*c^1 right

normal moss
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do what?

indigo scaffold
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to find a = 30

normal moss
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You have a system of two equations with two unknowns

indigo scaffold
#

no it was just a question

normal moss
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You are trying to figure out the values of these 2 unknowns that make both equations true

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You have figured out a = 30

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You can use that information

indigo scaffold
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alright

normal moss
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in the second equation

indigo scaffold
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19,2 = 30*c^1

normal moss
#

yes

indigo scaffold
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0,64 = c^1

normal moss
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yep

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hopefully we know what c^1 is

indigo scaffold
#

its 0,64

normal moss
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well yes

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I meant

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we usually write just c

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😂

indigo scaffold
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oh alr

normal moss
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not c^1

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Otherwise your equations would look like $7^1x^2y^1 = 18^1x^1$

flat frigateBOT
#

USS-Enterprise

indigo scaffold
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yeah lol

normal moss
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Right

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So we have figured out a and c

indigo scaffold
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we found c now so we replace x by 8

normal moss
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Well first

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write the function

indigo scaffold
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alright

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now what

normal moss
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What did you get

indigo scaffold
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0,84

normal moss
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what?

#

oh

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f(8)

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yes

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$f(x) = 30 \cdot \left(\frac{16}{25}\right)^x$

flat frigateBOT
#

USS-Enterprise

normal moss
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That is f(x)

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16/25 = 0,64

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And then just find f(8)

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which is approx. 0,84 yes

indigo scaffold
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yup

normal moss
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Notice how if you also input x = 0, 1, 2, 3

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The y in the table matches the output you get

indigo scaffold
normal moss
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But because we found the right function

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If the values didn't match, that would mean we had made a mistake

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easy way to test yourself

indigo scaffold
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oh yeah

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alright tysm

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.close

safe radishBOT
#
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normal moss
#

good luck!

safe radishBOT
#
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kind quartz
#

Can i get some help with this? I know how to do squeeze theorem but forget what to do with the fact its pi/x

plucky elk
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-1 <= sin(thing) <= 1

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doesn't matter what thing is, even if thing=pi/x

kind quartz
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So i just put it in as usual? ok

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We only recent started it so i was unsure lol

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Okay so working it out i have -root(x^3 + x^2) <= root(x^3 + x^2)sin(pi/2) <= root(x^3 + x^2). And working either of those out, they both are equal to zero, so its gotta be 0. Does that seem right?

plucky elk
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more specifically, the limit as x goes to zero of the left and right functions go to 0

kind quartz
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yes so its getting squeezed, as the name implies

kind quartz
plucky elk
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right

kind quartz
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Okay nice. i do have one more i fear but its easier, more just making sure im actually understanding

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When it comes to this, its l'hopital, yes? i dont quite understand how to do it

plucky elk
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factoring is better

kind quartz
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okay ill try that

plucky elk
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t-1 is a common factor to both numerator and denominator so you do polynomial division

kind quartz
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im struggling with the polynomial division, its been a while since i last did it. so like. we wanna divide t^4 - 1, by t-1. i lowkey forget how to do that so ill search it up rq i suppose

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okay i got t^3 + t^2 + t + 1 for the numerator, and t^2 + t + 1 for denominator

upper moat
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okay so

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Formula for difference of cubes is
(a-b)(a^2+ab+b^2)

plucky elk
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,w factor x^4-1

plucky elk
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,w expand (x+1)(x^2+1)

upper moat
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,w factor x^3-1

upper moat
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You notice

upper moat
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The (x-1) can cancel out

plucky elk
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should just be able to plug in t=1 now

kind quartz
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yesss cancel the t-1

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Okay so plugging in t=1 gave 4/3, which seems reasonable imo.

upper moat
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Yes

kind quartz
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okay thankyou! have a good day

#

.close

safe radishBOT
#
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safe radishBOT
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fringe drift
safe radishBOT
fringe drift
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can someone help me answer this

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do we divide by x

wild cape
fringe drift
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Wwould this be correct.

stoic dune
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Note it's not asking for the integrating factor, you're doing work you don't have to do

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<@&268886789983436800> scammer

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Thx you're bae

stoic dune
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A(x) is just the term multiplying y

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You've already found it, it's A(x) = 7

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Want to take a guess at B(x)?

fringe drift
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e^-3x

stoic dune
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Exactly!

fringe drift
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stuck after this step

stoic dune
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Just looking for the integral of tan(x)? Remember that tan(x) = sin(x)/cos(x)

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Can finish with u-sub

fringe drift
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oh so we rewrite it like that

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Is sec(3t) *cos(3t)=1

safe radishBOT
#

@fringe drift Has your question been resolved?

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safe radishBOT
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indigo scaffold
#

how can i find the value of 2 log_8 1

safe radishBOT
indigo scaffold
#

8^x = 1^2

quasi timber
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logₐ(1) always = 0 for 𝑎 > 1

indigo scaffold
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8^x = 0

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x = 0

muted sapphire
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?????

quasi timber
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muted sapphire
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everything ok opal?

indigo scaffold
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no

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is x = 0 right

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.close

safe radishBOT
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sinful citrus
safe radishBOT
sinful citrus
#

anyone wanna walk through this with me? I'm like 90% sure I can do it I just wanna make sure I'm doing it right since I don't have a solution for it

safe radishBOT
#

@sinful citrus Has your question been resolved?

safe radishBOT
#

@sinful citrus Has your question been resolved?

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blazing relic
#

i tried 250cos(1/3x)+750and that did NOT work so idk what to do

neat patrol
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plug in 15

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youre missing a factor for the (1/3)x part

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dont forget about the period of a cosine function

blazing relic
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i dont really know how to get those

sage rain
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your vertical shift of +750 is correct, as is your amplitude of 250

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so we have
y = 250 cos(something) + 750

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we know that this something takes the form Bx

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where B is the period of the function, which is 2pi divided by the frequency

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the maximum frequency was heard 6 times on [0,15] so we can tell that 5 full cycles occurred

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15 seconds / 5 cycles = 3

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Then, B= 2pi/3

flat frigateBOT
blazing relic
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hmm ok

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i think i see how we gotthat

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thank u

#

.solved

safe radishBOT
#
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silk cove
safe radishBOT
silk cove
#

,rotare

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,rotate

flat frigateBOT
silk cove
#

How to find Q1 and Q3?

safe radishBOT
#

@silk cove Has your question been resolved?

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silk cove
#

What is critical point?

safe radishBOT
light shoal
#

did you google it?

silk cove
#

I tried but I didn't understand it@bungo.the.original

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In the domain of function the point where it changes its direction

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???

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Or the derivative is 0

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Example |x-1|/x^2

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,w d/dx |x-1|/x^2

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,w d/dx of |x-1|

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Three points

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I guess two points because 0 is not in the domain

plucky elk
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Maybe you should plot the function

crystal pendant
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do you at least know stationary points for 2D graphs?

gritty sable
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Critical points are points where function becomes undefined, functions derivative become zero or undefined

silk cove
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,w d/dx |x-1|/x^2

gritty sable
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Critical points where derivative becomes zero are called stationary points too!

silk cove
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And what is critical point?

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Where is first derivative is 0 no?

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So this one is 0 at

crystal pendant
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for one variable functions, its where the first derivative is either 0 or undefined

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for multivariable functions, its where all first partial derivatives are either 0 or undefined

sage rain
silk cove
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so it is 0 at 1,2 yes

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And undefined at x=0

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But 0 is not in our domain

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.close

safe radishBOT
#
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fickle mantle
safe radishBOT
daring flume
#

just dropping by to say that you should be very careful writing exponents at near full font size.

fickle mantle
#

Oh

quasi bison
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yeah also line spacing should be like double what you got

sage rain
quasi bison
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you're on the right track though

sage rain
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2^2x + 16 -10(2^x) = 0 and solve the quadratic?

quasi bison
quasi bison
fickle mantle
#

Huh

daring flume
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try multiplying the entire equation by 2^x.

safe radishBOT
#

@fickle mantle Has your question been resolved?

quasi bison
#

welp

safe radishBOT
#
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fickle mantle
#

I’m did

#

I did it

safe radishBOT
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fickle mantle
safe radishBOT
sage rain
#

what did you do here

fickle mantle
median vigil
#

,rccw

flat frigateBOT
daring flume
# fickle mantle

preferably, when asked to show {expression 1} = {expression 2}, you should try to manipulate just one side to achieve the other.
but if your syllabus allows manipulation of both sides simultaneously via reversible operations, then your methodology could work.

fickle mantle
#

Oh ok

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I always get confused w this

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But how do I do the second one

daring flume
#

note that the question starts with the word "Hence".

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normally, when questions start with that word, it is an indication to use the information you have or derived from the previous subquestions.

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in this case, you have shown that the LHS of the equation is identical to the RHS in subquestion (1).
you are then given that the LHS of that equation is equal to some number.
what can you replace the LHS of the equation in (2) with to make it simpler?

safe radishBOT
#

@fickle mantle Has your question been resolved?

safe radishBOT
#
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latent knoll
#

hii. so this is a graph and i just need a confirmation whether or not this is correct. if you need me to translate something lmk. va is vertical asymptote, ha is horizontal and ka is oblique as.

'ekstremi' means extremes and 'nema rj' means no result

safe radishBOT
#

@latent knoll Has your question been resolved?

slender steeple
#

this one checks out

latent knoll
#

i am not entirely sure. i am just supposed to calculate a graph and to draw it?

slender steeple
#

you're asked to graph it?

latent knoll
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i basically need a domain, zeros, asymptotes and extremes and then draw it

slender steeple
#

is it also asking to label asymptotes and/or intercepts?

latent knoll
slender steeple
#

i see

latent knoll
latent knoll
#

cuz if it's not i have this variation as well

slender steeple
#

better than how i would've graphed it

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that's for sure

slender steeple
#

this is peculiar

latent knoll
slender steeple
#

you suddenly dip down on an x intercept?

latent knoll
latent knoll
slender steeple
#

this part is

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wrong

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but aside from that you should use your latest variation

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cause that's the correct one

latent knoll
#

what's wrong there

slender steeple
#

as per why, well it's not continuous

latent knoll
#

what does that mean

slender steeple
#

it has a sharp turn

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instead of being a smooth curve

latent knoll
#

i think they wont look at that that much tbh

latent knoll
slender steeple
#

the calculations check out

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but the graph is wrong sadly

slender steeple
latent knoll
#

well i've calculated that the extreme has no solutions but got root72 insteas of -40 so that sucks. that's 1 point despite an accurate result. the other part where i've failed is the graph ig

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istg if i fail math i'll die

slender steeple
#

just keep doing practice problems and you'll be fine

latent knoll
slender steeple
#

HAs only describe the END behaviour

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in between the HAs almost anything is fair game

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i'd reccomend using test values to check

latent knoll
#

yeah idk how to use that

slender steeple
#

basically

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values between the horizontal asymptotes

latent knoll
slender steeple
#

you're supposed to transition smoothly through the x intercept

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if you know what i mean

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sorta like this ig

latent knoll
#

oh..

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i hope my teacher doesn't minus me for that

slender steeple
#

he most likely will

latent knoll
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but how was i supposed to know ts

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i think that i did give it a little more space on my exam haha

slender steeple
latent knoll
slender steeple
#

one of them is that it's continuous

latent knoll
#

i swear if i lose like 4 points and i have 3 extra points and not enough for a passing grade i'll die

latent knoll
slender steeple
#

around 3-5

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depends on how important the graph is

latent knoll
# slender steeple i'd say

i did have to calculate the domain, zero points, asymptotes, extremes, write all that correctly and draw it on the graph which is did except for the 2 lines in the middle. do you rly think i'd lose so many points for that?

slender steeple
latent knoll
slender steeple
#

graph is smooth an continuous as it should be

latent knoll
#

but why is the left graph going down

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instead of up

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did i miscalculate smth or what

slender steeple
#

you mustve messed up

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on the end behaviour

latent knoll
#

let me calculate it again

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i got the correct drawing now

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the thing is.. i dont remember how i drew it

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i think i might've been drew it this way bcz i rmb paying attention to the 3,99 4,01 -3,01 -2,99... and that is how i drew this graph correctly.. if only i could remember

slender steeple
latent knoll
#

sharp turn?

slender steeple
#

no

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random shift that is not needed

latent knoll
#

eh whatever i cant remember. let's just pray i drew it correctly

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only God can save me now

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thanks for ur time. i appreciate it

slender steeple
#

ok

latent knoll
#

.close

safe radishBOT
#
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safe radishBOT
#
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tired kernel
#

Ankita travels 14 km to her home partly by rickshaw and partly by bus She takes half an hour if she travels 2 km by rickshaw and remaining distance by bus . On the other hand , if she travels 4 km by by rickshaw and takes 9 mins longer Find the speed of the rickshaw and of the bus .

tired kernel
#

Need guidance how to solve such kind of question

hard crest
#

probably easiest thing to do here is to say the rickhsaw travels R km/h, and the bus travels B km/h

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and set up a system of equations

tired kernel
#

took x and y respectively

hard crest
#

actually you might choose to say the rickshaw travels at R h/km instead, probably easier to work the numbers

hard crest
tired kernel
#

i tried making 2 equations but got stuck at point which makes me think my equations are wrong

hard crest
#

hmm ok

#

what were your equations and reasoning?

tired kernel
#

i am sharing just wait a moment i am on laptop with no camera so it's little hard to share my progress

#

equation 1

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i took the time on one side and added the time taken my both vehicals

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after converting it into distance/speed

hard crest
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right ok yea so

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you kinda rocked yourself a little here

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but if you write it like this

tired kernel
#

Are the equations correct?

hard crest
#

$4(\f1x) + 16(\f1y) = \f{13}{20}$ etc

flat frigateBOT
#

hayliänus austrǎlis

hard crest
#

then you can solve for 1/x and 1/y

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yea they seem right to me

#

13/20 is 39/60

tired kernel
#

ahh i am confused how do i solve it further? taking 4 common?

hard crest
#

well clearing denominators by multiplying by 20 could be nice, but the point is that you take "1/x" as a Thing

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and solve for 1/x and 1/y like you would any system of equations

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you can even replace 1/x with X (capital) if you want

tired kernel
#

oh alr got it

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let me solve it further like that then

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after trying to solve it further i am getting q(1/y) = 7/320 by using elimination methord

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which i think might be wrong i think

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i took 1/7 as q it is not multiplied up there

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oh wait i might have realised by mistake

hard crest
#

q?

tired kernel
#

i took 1/x as p

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and 1/y as q

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i did 12*2 = 32 by mistake let me correct it

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but still getting 7/160

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as q

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i did this , is this correct?

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i tried to elimination of p in this

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by multiplying 2p+12q=1/2

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into 2

hard crest
#

sure

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(maybe do -2)

tired kernel
#

but after doing that and then using elimination

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i am getting

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8q=7/20

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trouble is on the rhs side i think

hard crest
#

what's wrong with it

tired kernel
#

how will i solve 8q=7/20 further?

hard crest
#

well

tired kernel
#

it will become very complex

hard crest
#

seeing as you're multiplying 8 by q, how about try dividing by 8

tired kernel
#

ahh i did'nt understand that

#

you want me to do it like q=7/160?

hard crest
#

sure

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and so now we have 1/y = 7/160

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so we can do a little upsy daisy and say y = 160/7

tired kernel
#

yep

hard crest
#

now what units were those?

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what was y supposed to mean?

tired kernel
#

speed of bus

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x=speed of rickshaw and y as speed of bus

hard crest
#

in what units?

tired kernel
#

km/h

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hmm i think i did it wrong

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when i subsitute value of y=160/8 into equation

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i get x=-80

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and it's impossibel for speed to be in negative

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i am doing mistake in elimination i think

hard crest
#

no i get the same from your system

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let me check over what you did

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oh 16q is wrong

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should be 10q

lean swan
#

it's my first time here im new here

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in this server

tired kernel
#

hmm actually i wanted to learn step by step how to solve such problem i do not just want the solution

#

oh

lean swan
#

k so im in 10th grade so we were thought 2 ways of solving this problem One is the elimination method and the other is substitution method and they both work perfectly fine in these simultaneous pairs of linear equations

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which grade are you in by the way

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I mean I'm not really a good teacher but I can try to make you understand

tired kernel
#

i got it

#

in the equation

#

i wrote 16q

#

the remaining distance was 10 km not 16

#

that why i was getting stuck

lean swan
tired kernel
hard crest
#

hey shado i appreciate your help but i think we're pretty much there

lean swan
#

it's from a combined sample paper Ik

tired kernel
#

i am in 9 th i am studying 10 th material

lean swan
tired kernel
#

wait let me just solve the question first

#

then talk about this

lean swan
#

kk take ur time

tired kernel
#

y=40 km/h speed of bus

#

x=10 km/h

#

finally solved

#

@hard crest Thank you very much for helping

hard crest
tired kernel
#

and there are some class mates of mine who are literally preparing for jee since class 6 th

#

now they have completed the whole syllabus of 10 th

#

and heading to study for 11 th instead of preparing for 9 th final

#

since they have already study all that long ago

#

so i also started studying 10 th material as soon as i finished 9 th

#

so i can also head on 11 th

#

and start preparing for jee as soon as possible

#

seeing the compition

#

ahh you here to read all this or should i close the channel ? @lean swan

#

.close

safe radishBOT
#
Channel closed

Closed by @tired kernel

Use .reopen if this was a mistake.

lean swan
#

yeaaa

#

correct

lean swan
#

nice ambition u aiming JEE?

tired kernel
#

yep

#

to get an iit somehow

safe radishBOT
#
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lean swan
tired kernel
#

ahh we opened a help channel by mistake

#

let's talk in personal dm

stiff magnet
#

offline batches are better

tired kernel
#

.close

#

i cannot even close it bruh

#

well nvm btw

#

what batch should i take

#

when i go in 11 th?

safe radishBOT
#
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granite flower
#

Here you are

safe radishBOT
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mellow tide
#

So I'm self-studying math right now in order to prepare for my math test next week and I'm currently stuck on a problem in my math book. Since it's in Norwegian I will try to translate closely as possible over to english.

A company got a bill of 47500 kr (Norwegian kr to clarify), to repair a roof of one of the city farms.
The company has 20000kr in their account and bills out around 2500kr for every apartment.

So I solved problem A to make a model being K(x) = 2500x + 20000kr

Now I'm stuck on problem B to find the area of validity. I thought I managed to solve it by doing 2500x/2500 which ends up being 0 since X, and then 20000kr/2500 which is 8. So the X would be between 0 and 8.

The issue here is, once I looked at the answer sheet in the book, it says it's supposed to be that X is between 0 and 16. So I don't quite understand how it became like that. I feel like I'm missing something in order to solve it and I been wrapped around this problem for a while now.
I cannot use any assisted tools like calculator and etc. I can only do it written.

mint plume
#

send the norwegian problem too

#

!xy

safe radishBOT
#

Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.

mellow tide
#

In the first picture is the one I’m doing, the second picture is doing similiar problem in a different section of the book.

#

In text format:

Et borettslag med 16 leiligheter har fått en regning på 47500kr for reparasjoner av taket på en av bygårdene. Borettslaget har 20000kr på konto og sender i tillegg ut en faktura på 2500kr til hver leilighetene.

Problem A) Lag en modell, K(x), som viser hvor mye borettslaget har på konto etter at x leiligheter har betalt fakturaen. So K(x) = 2500x + 20000kr.
Problem B) (Which I'm currently stuck at), Bestem et gyldighetsområde for modellen.
So I attempted 2500x/2500 which is 0 due to X, then do 20000/2500, which becomes 8. I don't know if the answer sheet is wrong or if it's correct, but the supposed answer is that X is between 0 and 16. I don't really know how they got that answer at all. It feels like I'm missing something to solve it.

safe radishBOT
#

@mellow tide Has your question been resolved?

mellow tide
#

<@&286206848099549185>

#

Gonna attempt the other problems by myself, but I can't find out how the X is between 0 and 16. I've been trying to brainstorm any possible solutions to find the part that I'm missing in order to solve it.

#

Nvm, I think I managed to solve it. Since X is between 0 and 8, then the y has to be 16. (0, 16).

#

.close

safe radishBOT
#
Channel closed

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safe radishBOT
#
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timid echo
safe radishBOT
timid echo
#

i know the method to solve this but kinda bad at it

opaque fern
#

Elaborate

daring flume
#

$\frac{5^2}{625^5}$?

flat frigateBOT
#

Nicole

timid echo
#

yes

daring flume
#

so what is your confusion with this?

timid echo
#

so um 5^2 ÷ 625^5 = 5^2 ÷ (5^4)^5

#

so now i cant find the answer, it shows some random ass letters and symbols on cal

flat frigateBOT
daring flume
#

use the power of power rule to settle the denominator first.

timid echo
#

ok

daring flume
#

then it should be clear how to proceed.

timid echo
#

so (just powers) it is 2-20 right?

#

cause 5^2 and 5^20

daring flume
#

correct.

timid echo
#

ok so the answer results 5^-18

daring flume
#

looks good.

timid echo
#

ok, thanks i couldnt verify, cal shows something weird i havent learnt

opaque fern
# timid echo

Good time to stop using the division symbol by the way

#

Or things will get annoying (and confusing)

timid echo
daring flume
#

prefer using a fraction to express division.

timid echo
#

ok

#

got it

opaque fern
#

,, \frac ab

daring flume
flat frigateBOT
opaque fern
#

Thats the LaTeX command if you are curious

timid echo
#

hm ok

daring flume
opaque fern
#

no

#

You can try that

timid echo
#

thank you guys, now should i close this or its alright

daring flume
#

,, \frac ab

flat frigateBOT
#

Nicole

opaque fern
#

Yeah close it

daring flume
#

oh, interesting. I'm more used to math mode.

timid echo
#

.close

safe radishBOT
#
Channel closed

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timid echo
daring flume
#

yes, preferably.

safe radishBOT
#
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restive turret
#

The drawing in notebook is mine with the auxiliary construction, the other with a zoom and that hasn't the line CD, is the original from the original problem.

restive turret
#

Hypothesis or Data: 1. AD is perpendicular to AB, 2. BC is perpendicular to AB. 3. AD ll BC. Auxiliary Construction: It draws a perpendicular from vertex C to D this perpendicular will be called CD. Thesis: Prove that ABCD is a rectangle.

#

I want someone to check if my proof is correct

#

The right is the original drawing, the left is mine with the auxiliary construction

safe radishBOT
#

@restive turret Has your question been resolved?

restive turret
#

<@&286206848099549185>

#

<@&286206848099549185>

sour bolt
sudden seal
#

yess

restive turret
#

Srry

#

But can you help me pls

sudden seal
#

give me 5 minutes, im helping one right now, will be here in 5

restive turret
#

Ok

safe radishBOT
#

@restive turret Has your question been resolved?

safe radishBOT
#

@restive turret Has your question been resolved?

restive turret
#

<@&286206848099549185>

restive turret
#

<@&286206848099549185>

#

<@&286206848099549185>

#

Pls i need help

#

Well a check

#

<@&286206848099549185>

#

<@&286206848099549185>

fickle monolith
#

Yo chill

dreamy meadow
#

bro

#

dont spam

restive turret
#

But pls i need you to check me pls

dreamy meadow
#

If you need help ping once

#

theres another guy coming to help

restive turret
#

Oh ok

dreamy meadow
#

if you spam ping any more we need to ping a mod

#

dont spam cuz everyone with that role gets absolutley cooked

restive turret
#

So what do i put?

dreamy meadow
#

read the ticket info, it says "ping helpers once after 15 mins if no one comes"

restive turret
#

Bro it happens 2 hrs

dreamy meadow
#

ok so dont spam ping then

restive turret
#

Ok

#

But pls help, i've been wairing 2 hrs

sudden seal
#

ok give it

#

what u want us to check

#

ohh fckk my bad

#

i was working over smtjh

restive turret
#

Hypothesis or Data: 1. AD is perpendicular to AB, 2. BC is perpendicular to AB. 3. AD ll BC. Auxiliary Construction: It draws a perpendicular from vertex C to D this perpendicular will be called CD. Thesis: Prove that ABCD is a rectangle.

#

The right is the original drawing, the left is mine with the auxiliary construction

sudden seal
#

its only a bit correct

restive turret
#

Why only a bit?

#

Why not entirely correct??

sudden seal
#

Your written proof does not explicitly justify:

Why CD ∥ AB

Why having two pairs of parallel sides + right angle ⇒ rectangle

#

Since AD ⟂ AB and BC ⟂ AB, we get AD ∥ BC.
Construct CD ⟂ AD. Since AD ⟂ AB, CD ∥ AB.
Thus, opposite sides are parallel and one angle is right.
Hence, ABCD is a rectangle.

#

use this it would be good

restive turret
#

Oh so the form that i write is wrong but the purpose is good we can say??

naive dragon
restive turret
naive dragon
restive turret
#

Well by the hypothesis CB is perpendicular to AB, and AD is perpendicular to AB and as CD is a perpendicular, CD is perpendicular to CB and AD

sudden seal
#

here

#

i got it on ss

naive dragon
#

That would be all you need to complete the proof

naive dragon
restive turret
#

Yeah but CD is a perpendicular from vertex C to D, so CD is perpendicular og CB and AD

sudden seal
#

bro we can construct CD perpendicular AD and since AD is already perpendicular to AB, we willl have CD parallel to AB

naive dragon
#

I meant OP's

sudden seal
#

yea i got i

#

it

restive turret
sudden seal
#

both pairs of opposite sides are parallel, so ABCD is parallelogram and because DAB = 90*, ABCD IS rectangle

naive dragon
naive dragon
sudden seal
#

im just gonna send the whole solution

naive dragon
#

!nosols lol

safe radishBOT
#

As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.

sudden seal
#

oopss

naive dragon
#

Why do you think I'am doing this for

sudden seal
#

it slipped from my mindd

restive turret
#

I'm gonna write it

#

And you check me

sudden seal
#

i have been awake from quitee too mcuh time

#

my head is goinn

#

WIII

restive turret
#

Gimme 10 min

sudden seal
#

hm

restive turret
#

And i'll write it and check

#

Me pls

#

To finish this odyssey

#

@sudden seal @naive dragon

#

Only check me

#

Pls

#

And we finish this odyssey

naive dragon
#

Yeah that seems good

restive turret
#

Ok

#

Finally

#

So

#

Thanks!!!!!!!!!!!! @naive dragon @sudden seal @dreamy meadow @sour bolt @fickle monolith

#

.close

safe radishBOT
#
Channel closed

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safe radishBOT
#
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verbal flare
#

hello

safe radishBOT
slate pebble
#

what is your question

verbal flare
#

i need help understanding this

#

trigo

open junco
verbal flare
#

was i?

open junco
verbal flare
#

alr

#

uhh

#

cos like im really fing clueless after bi done that 😭

open junco
#

Like assume the case where tanx is not 0 and cancel out the numerator?

verbal flare
#

uhh

#

yea im still here

#

im racking my brain

#

what d you mean assume the case where tanx is not 0 bruhhhhhh

#

not like im criticizing you but i cant seem to understand

slate pebble
#

if tan(x) is zero you would be dividing by zero

open junco
#

I mean divide both sides by tanx yk and you cant divide by 0

slate pebble
#

but because it is stated in the original equation that tan(x) is in the denominator we can assume it is not zero

verbal flare
#

ohhhh ok

#

i understand why its not zero

open junco
verbal flare
#

ok

slate pebble
#

that's true

#

mb

verbal flare
#

alr so

#

$tan 2x / tan x$

flat frigateBOT
verbal flare
#

so do i use the double angle idenities in the numerator?

#

like

icy aspen
verbal flare
#

so

#

hold on ill be back

#

i need to reset my ipad

#

because of some keyflicks

#

so

#

$(2tan x/1-tan^2x)/tanx$

flat frigateBOT
open junco
verbal flare
#

alr thx

open junco
verbal flare
#

yes ttsm

#

tysm

#

i undertsand

#

tjhxxxxxxx

#

.close

safe radishBOT
#
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safe radishBOT
#
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vocal stirrup
#

000.33333333330000*10⁹

safe radishBOT
vocal stirrup
#

I understand I have to multiply, but I don't understand how

#

I haven't done any math in three years because I dropped out of middle school, so I was trying to refresh my memory before getting back into school but everything looks scary and confusing, I asked around for help and I still couldn't understand a lot of it

winged flare
#

shift the dot right 9 times

vocal stirrup
winged flare
#

just 000333333333.30000

vocal stirrup
#

Ok got it

#

That's the answer?

winged flare
#

yeah

#

when multiplying by 10^n shift the dot right n times

#

for positive n

vocal stirrup
#

Ohh I see thank you!! 🩷

#

.close

safe radishBOT
#
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safe radishBOT
#
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solar sand
#

Are there any alternative ways to find the matrices A^2 A^3 A^4 etc to compute Bn matrix while solving the questions of path matrix? Manually counting the paths causes a lot of error in exams, so was wondering if there are alternative ways to find those matrices easily

mortal sandal
#

Well, there's matrix multiplication

#

Especially if you have access to a graphing calculator during exams

solar sand
mortal sandal
#

what kinda calculator does that 💀

#

ig manual matrix multiplication then

solar sand
mortal sandal
#

Well you don't need to find A^3 to find A^4

#

You can just square A^2 again

#

But if you don't have a calculator that can handle them then as far as I know it's manual matrix mult or count paths

#

What kind of calculator do you even have

solar sand
mortal sandal
#

oh I didn't know those had matrices at all

#

welp if you're allowed to use a graphing calculator you can buy one or see if you can borrow one

solar sand
#

alright

#

thanks

#

.close

safe radishBOT
#
Channel closed

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mortal sandal
#

np

safe radishBOT
#
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quiet hollow
#

I’m stuck on this question bc I can’t find any common factors between 2 & 9

lean otter
open wedge
#

factor?

open wedge
lean otter
#

unless you assume all this is 0

open wedge
lean otter
#

mid-term?

open wedge
#

ay ay

#

don't spoil the answers yet

lean otter
#

oops

open wedge
#

3 specifically

lean otter
open wedge
#

but i don't really use that

burnt notch
#

Me neither, actually in Italy we aren't even taught it

lean otter
#

I do completing square if one value of x is a fraction

#

otherwise its mid term

#

its a matter of preference really

open wedge
#

the 3rd method is the one i use the most

#

it's to find the roots of the polynomial

quiet hollow
#

It’s Triomal factoring

lean otter
#

then you are looking for mid term split i assume

open wedge
lean otter
burnt notch
open wedge
#

then split the midterm into (first number)x + (second number)x

#

that's midterm split

lean otter
#

-# too many people i back out

burnt notch
#

<@&268886789983436800>

raw pivot
#

<@&268886789983436800>

quiet hollow
open wedge
#

you need to find 2 numbers that multiply to -18

#

and add to 3

lean otter
#

what were trying to do with split up the 3

#

into 2 new factors/things

#

so when you split it, the numbers should multiply to -18 and add up to 3

quiet hollow
#

You got like a visual I can follow

#

Bc I don’t get I

#

It

open wedge
#

search up on google for midsplit

lean otter
#

uh wait let me doodle it for you

open wedge
#

$x^2 - 5x + 6$ for example

flat frigateBOT
#

1 divided by 0 equals Infinity

open wedge
#

two numbers that times to $1 \cdot 6$ and add up to $-5$ is $-2$ and $-3$

flat frigateBOT
#

1 divided by 0 equals Infinity

open wedge
#

so i'd split $x^2 - 5x + 6$ into $x^2 - 2x - 3x + 6$

flat frigateBOT
#

1 divided by 0 equals Infinity

open wedge
#

$= x(x - 2) - 3(x - 2) = (x - 2)(x - 3)$

flat frigateBOT
#

1 divided by 0 equals Infinity

open wedge
#

done factorizing

lean otter
#

aaand I cant paste images

#

great

open wedge
#

lol

lean otter
#

nvm it works now

#

my handwriting is a bit messy

open wedge
lean otter
#

but you get the gist of it

#

WAIT WAIT LET ME MAKE A BETTER ONE

#

Stop roasting 😭

open wedge
flat frigateBOT
#

1 divided by 0 equals Infinity

quiet hollow
#

I understood everything but what that last row is supposed to say

open wedge
#

well idk

#

u + y are 2 numbers that add up to 3

#

and times to make -18 i suppose?

#

@quiet hollow

quiet hollow
#

I already have my -18 by doing 9(-2)

lean otter
#

.

open wedge
#

you need to find

#

2 numbers

lean otter
open wedge
#

that add up to -18

#

and times to make 3

lean otter
flat frigateBOT
#

noonebtw

open wedge
#

9 + (-2) is not equal to 3

open wedge
lean otter
#

yeah

#

actually

#

try and find the number yourself

open wedge
lean otter
#

hint: both are divisible by 3

open wedge
#

smart

#

i have 2 more ways to introduce dw

lean otter
#

thats x

open wedge
#

complete the square

lean otter
#

but close enough 😆

open wedge
#

and find the roots

lean otter
#

you can disregard completing the square here

#

since theres no RHS

quiet hollow
#

I used an X method

quiet hollow
#

.close

safe radishBOT
#
Channel closed

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Use .reopen if this was a mistake.

lean otter
#

whar

safe radishBOT
#
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open wedge
#

i can still do it without the RHS

safe radishBOT
open wedge
#

.close

safe radishBOT
#
Channel closed

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lean otter
#

looks "complex"

#

compared to something like a mid term

open wedge
#

imagine accidentally opening a channel...

lean otter
#

no need to

open wedge
lean otter
#

I am aware

open wedge
#

ts rarely happens

#

it's like the 1st time happening to me or smth

safe radishBOT
#
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earnest mirage
#

Hello, could someone check if this proof looks good please?
⁨```latex
\begin{Theorem}
Assume $n \in \bZ$. If $5n^2 + 3$ is even, then $n$ is odd.
\end{Theorem}

\begin{proof}
We use the contrapositive.
Suppose $n$ is even.
Then, $n = 2k$ for some integer $k$.
So, $5n^2 + 3 = 5(2k)^2 + 3 = 20k^2 + 2 + 1 = 2(10k^2 + 1) + 1$.
Since $k$ is an integer, so is $10k^2 + 1$.
Then, $5n^2 + 3 = 2l + 1$, where $l = 10k^2 + 1$.
Thus, by the definition of odd integers, $5n^2 + 3$ is odd.
Therefore, by the contrapositive, if $5n^2 + 3$ is even, then $n$ is odd.
\end{proof}

flat frigateBOT
#

Mor Bras

tardy mango
safe radishBOT
#

@earnest mirage Has your question been resolved?

earnest mirage
#

Thanks!

safe radishBOT
#
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earnest mirage
#

Hello, could someone check if this proof looks good please?
⁨```latex
\begin{Theorem}
Assume $n \in \bZ$. If $8 \nmid (n^2 - 1)$, then $n$ is even.
\end{Theorem}

\begin{proof}
We use the contrapositive.
Suppose $n$ is odd.
Then, $n = 2(2k) + 1 = 4k + 1$ for some integer $k$.
So, $n^2 - 1 = (4k + 1)^2 - 1 = 16k^2 + 8k + 1 - 1 = 8(2k^2 + k)$.
Since $k$ is an integer, so is $2k^2 + k$.
Thus, by the definition of divisibility, $8 \mid n^2 - 1$.
Therefore, by the contrapositive, if $8 \nmid (n^2 - 1)$, then $n$ is even.
\end{proof}

flat frigateBOT
#

Mor Bras

stoic dune
#

Suppose n is odd: I'll choose n = 3.

You suggest that 3 = 4k + 1 for some integer k. What's k?

#

I see that n is not just any odd, but a specific odd. An odd kind of odd

#

But ultimately you've now proven that if 8 doesn't divide (n² - 1), then n is not of the form 4k + 1

visual kraken
#

After fixing the part Kaynex mentioned you'll probably have just one extra step, but otherwise the proof looks nice

earnest mirage
#

Here's the fix:
⁨```latex
\begin{Theorem}
Assume $n \in \bZ$. If $8 \nmid (n^2 - 1)$, then $n$ is even.
\end{Theorem}

\begin{proof}
We use the contrapositive.
Suppose $n$ is odd.
Then, $n = 2k + 1$ for some integer $k$.
Now, either $k$ is even or odd.

\begin{case}
Suppose $k$ is even.
Then, $k = 2l$ for some integer $l$, and then $n = 2(2l) + 1 = 4l + 1$.
So, $n^2 - 1 = (4l + 1)^2 - 1 = 16l^2 + 8l + 1 - 1 = 8(2l^2 + l)$.
Since $l$ is an integer, so is $2l^2 + l$.
Thus, by the definition of divisibility, $8 \mid n^2 - 1$.
\end{case}

\begin{case}
Suppose $k$ is odd.
Then, $k = 2l + 1$ for some integer $l$, and then $n = 2(2l + 1) + 1 = 4l + 3$.
So, $n^2 - 1 = (4l + 3)^2 - 1 = 16l^2 + 24l + 9 - 1 = 8(2l^2 + 24l + 1)$.
Since $l$ is an integer, so is $2l^2 + 24l + 1$.
Thus, by the definition of divisibility, $8 \mid n^2 - 1$.
\end{case}

In both cases, we have that if $n$ is odd, then $8 \mid n^2 - 1$.
Therefore, by the contrapositive, if $8 \nmid (n^2 - 1)$, then $n$ is even.
\end{proof}

flat frigateBOT
#

Mor Bras

queen ingot
earnest mirage
#

Fixed 👌
⁨⁨```latex
\begin{proof}
We use the contrapositive.
Suppose $n$ is odd.
Then, $n = 2k + 1$ for some integer $k$.
Now, either $k$ is even or odd.

\begin{case}
Suppose $k$ is even.
Then, $k = 2l$ for some integer $l$, and then $n = 2(2l) + 1 = 4l + 1$.
So, $n^2 - 1 = (4l + 1)^2 - 1 = 16l^2 + 8l + 1 - 1 = 8(2l^2 + l)$.
Since $l$ is an integer, so is $2l^2 + l$.
Thus, by the definition of divisibility, $8 \mid n^2 - 1$.
\end{case}

\begin{case}
Suppose $k$ is odd.
Then, $k = 2l + 1$ for some integer $l$, and then $n = 2(2l + 1) + 1 = 4l + 3$.
So, $n^2 - 1 = (4l + 3)^2 - 1 = 16l^2 + 24l + 9 - 1 = 8(2l^2 + 3l + 1)$.
Since $l$ is an integer, so is $2l^2 + 3l + 1$.
Thus, by the definition of divisibility, $8 \mid n^2 - 1$.
\end{case}

In both cases, we have that if $n$ is odd, then $8 \mid n^2 - 1$.
Therefore, by the contrapositive, if $8 \nmid (n^2 - 1)$, then $n$ is even.
\end{proof}

queen ingot
#

looks good besides that one issue

flat frigateBOT
#

Mor Bras

earnest mirage
#

.close

safe radishBOT
#
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safe radishBOT
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vagrant steppe
safe radishBOT
vagrant steppe
#

How come we don't times the ^-2 or 2 to the imaginary ^1 the 1 has

vagrant steppe
#

Or is that not a rule in these kind of situations

solar hazel
#

what 1?

normal moss
#

So I can't answer that

vagrant steppe
#

Wait I think I understand

normal moss
#

Ah

vagrant steppe
#

Right?

#

Or should I have flipped the 1 and exponent first

solar hazel
#

are you talking about like (a^b)^c = a^(bc)?

vagrant steppe
#

Because like I know 1^2 is just 1
But don't that 1 really have a ^1 to it too

solar hazel
#

i guess but it doesn't make a difference

vagrant steppe
#

I guess my question now is how would you have worked it out

#

Bc I flipped it last

burnt notch
#

(stuff² = stuff × stuff)

vagrant steppe
#

But maybe I should have done that first

#

Should I have flipped to get rid of the ^- first

burnt notch
#

<@&268886789983436800>

burnt notch
flat frigateBOT
#

Alberto Z.

burnt notch
#

(That happens because b•c = c•b, since multiplication is commutative)

vagrant steppe
#

I'm just confused because -1^-2 is -1

#

And then the exponent would be -1^-2

Because that 1 has an ^1 and the ^-2 times it which then again just gives you negative one

So that's why I'm wondering if flipping first just idk

#

Because if I flip it now I still get stuck with a -1

#

WAOT

#

No

burnt notch
#

$$(-1)^{-2} \neq -1^{-2}$$

vagrant steppe
#

Bc -1*-1 is 1

flat frigateBOT
#

Alberto Z.

vagrant steppe
#

Oh

#

So here I wouldn't ex knowledge how the -1 technically has a ^1?

burnt notch
#

$$(-1)^{-2} = \frac{1}{(-1)^2} = \frac{1}{(-1) \times (-1)} = \frac11 = 1$$

flat frigateBOT
#

Alberto Z.

vagrant steppe
#

Doesnt the 1 have an imaginary exponent of 1?

normal moss
#

Almost everything has an exponent of 1

#

"imaginary" is unfortunate wording though

vagrant steppe
#

She sorry

#

Ah*

normal moss
#

4^2

#

is just (4^2)^1

vagrant steppe
#

Is that an example

normal moss
#

Yes

vagrant steppe
#

It's just my fault I over think and complicate everything lol

#

I think I'm okay

#

Thank you guys I'm sorry that was stupid

normal moss
#

Well but do you get it now?

#

No need to apologize

vagrant steppe
#

I think

safe radishBOT
#

@vagrant steppe Has your question been resolved?

#
Channel closed

Closed by @vagrant steppe

Use .reopen if this was a mistake.

vagrant steppe
#

.close

safe radishBOT
#
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earnest mirage
#

Hello, could someone check if this proof looks good please?
⁨⁨⁨⁨⁨```latex
\begin{Theorem}
Assume $m,n \in \bZ$. If $m^2(n^2 + 5)$ is even, then $m$ is even or $n$ is odd.
\end{Theorem}

\begin{proof}
We use the contrapositive.
Suppose $m$ is odd and $n$ is even.
Then, by the definition of odd and even integers, $m = 2k + 1$ and $n = 2l$ for some integers $k$ and $l$.
And so,
\begin{align*}
m^2(n^2 + 5) &= (2k + 1)^2((2l)^2 + 5)\
&= (2k^2 + 4k + 1)(4l^2 + 5)\
&= 16k^2l^2 + 20k^2 + 16kl^2 + 20k + 4l^2 + 4 + 1\
&= 2(8k^2l^2 + 10k^2 + 8kl^2 + 10k + 2l^2 + 2) + 1\
\end{align*}

Since $k$ and $l$ are integers, so is $8k^2l^2 + 10k^2 + 8kl^2 + 10k + 2l^2 + 2$.
Thus, by the definition of odd integers, $m^2(n^2 + 5)$ is odd.
Therefore, by the contrapositive, if $m^2(n^2 + 5)$ is even, then $m$ is even or $n$ is odd.
\end{proof}

earnest mirage
wild cape
#

the claim is supposed to say 5 instead of 1?

earnest mirage
wild cape
#

ok so typos in conclusions too

earnest mirage
wild cape
#

,w expand (2k+1)^2((2l)^2+5)

woven hound
#

I think you've way overcomplicated this

flat frigateBOT
#

Mor Bras

woven hound
#

Like the approach is technically correct but a bit overkill I think

#

I would do assume m^2 (n^2 + 5) is even, and assume m is odd.
Goal: Show n is odd

wild cape
#

the algebra is right so proof is good

earnest mirage
earnest mirage
woven hound
#

if you want to try that approach it's a direct proof

earnest mirage
#

The exercise stated to use the contrapositive

woven hound
earnest mirage
#

Otherwise, by direct proof, then only given is that m2(n2 + 5) is even

safe radishBOT
#

@earnest mirage Has your question been resolved?

earnest mirage
woven hound
#

Direct proof is:

  1. Assume m^2(n^2+5) is even
  2. Show m is even OR n is odd
#

You can do step 2 by assuming m is odd implies n is odd

earnest mirage
#

Assuming m odd makes "m odd or n even" true automatically, isnt it?

#

Oh I see

#

Yes

earnest mirage
#

.close

safe radishBOT
#
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safe radishBOT
#
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earnest mirage
#

Hello, could someone check if this proof looks good please?
⁨```latex
\begin{Theorem}
Assume $m,n \in \bZ$. If $(m^2 + 4)(n^2 - 2mn)$ is odd, then $m$ and $n$ are even.
\end{Theorem}

\begin{proof}
We use the contrapositive.
Suppose either $m$ is odd or $n$ is odd.

\begin{case}
Assume $m$ is odd.
Then, by the definition of odd integers, $m = 2k + 1$ for an integer $k$.
So, $(m^2 + 4)(n^2 - 2mn) = (4k^2 + 4)(n^2 - 4kn) = 2(2k^2 + 2)(n^2 - 4kn)$.
Since $k$ and $n$ are integers, so is $(2k^2 + 2)(n^2 - 4kn)$.
Thus, by definition of even integers, $(m^2 + 4)(n^2 - 2mn)$ is even.
\end{case}
\begin{case}
Now assume $n$ is odd.
Then, by the definition of odd integers, $n = 2k + 1$ for an integer $k$.
So, $(m^2 + 4)(n^2 - 2mn) = (m^2 + 4)(4k^2 - 4mk) = 2(m^2 + 4)(2k^2 - 2mk)$.
Since $k$ and $m$ are integers, so is $(m^2 + 4)(2k^2 - 2mk)$.
Thus, by definition of even integers, $(m^2 + 4)(n^2 - 2mn)$ is even.
\end{case}

We showed that if $m$ is odd or $n$ is odd, then $(m^2 + 4)(n^2 - 2mn)$ is even.
Therefore, by the contrapositive, if $(m^2 + 4)(n^2 - 2mn)$ is odd, then $m$ and $n$ is even.
\end{proof}

flat frigateBOT
#

Mor Bras

hard crest
#

it's probably fine but you've posted a lot of these very sledgehammery proofs so far. Do you not have something that says if an odd number is equal to a * b, then both a and b must be odd?

earnest mirage
#

Not really, as far as I can see

hard crest
#

wait it's not fine, i don't get this part --- it looks like you've assumed m = 2k?

#

wait this isn't even true

#

m = n = 1
(m^2 + 4)n(n-2m) = 5 * 1 * -1 = -5

earnest mirage
#

I made a mistake typing the theorem and the proof, let me fix it

austere goblet
#

it also seems like you may find it useful to check your own proofs

#

while we can give you second opinions, it's always good to be able to do so without external assistance (or with minimal assistance)

#

esp. on typos and algebra mistakes

earnest mirage
#

⁨```latex
\begin{Theorem}
Assume $m,n \in \bZ$. If $(m^2 + 4)(n^2 - 2mn)$ is odd, then $m$ and $n$ are odd.
\end{Theorem}

\begin{proof}
We use the contrapositive.
Suppose either $m$ is even or $n$ is even.

\begin{case}
Assume $m$ is even.
Then, by the definition of even integers, $m = 2k$ for an integer $k$.
So, $(m^2 + 4)(n^2 - 2mn) = (4k^2 + 4)(n^2 - 4kn) = 2(2k^2 + 2)(n^2 - 4kn)$.
Since $k$ and $n$ are integers, so is $(2k^2 + 2)(n^2 - 4kn)$.
Thus, by definition of even integers, $(m^2 + 4)(n^2 - 2mn)$ is even.
\end{case}
\begin{case}
Now assume $n$ is even.
Then, by the definition of even integers, $n = 2k$ for an integer $k$.
So, $(m^2 + 4)(n^2 - 2mn) = (m^2 + 4)(4k^2 - 4mk) = 2(m^2 + 4)(2k^2 - 2mk)$.
Since $k$ and $m$ are integers, so is $(m^2 + 4)(2k^2 - 2mk)$.
Thus, by definition of even integers, $(m^2 + 4)(n^2 - 2mn)$ is even.
\end{case}

We showed that if $m$ is even or $n$ is even, then $(m^2 + 4)(n^2 - 2mn)$ is even.
Therefore, by the contrapositive, if $(m^2 + 4)(n^2 - 2mn)$ is odd, then $m$ and $n$ is even.
\end{proof}

flat frigateBOT
#

Mor Bras

austere goblet
#

maybe on your next attempt, you can show what you think is mistaken that warrants a second opinion from us

#

helps build your self-confidence too

earnest mirage
austere goblet
#

mhm. the idea is that you can produce and verify proofs

#

I don't see anything wrong on a skim but I'm outside atm

earnest mirage
#

I also understand the work volunteers put in checking my work whenever possible, and I appreciate it whenever someone reads and point out the errors, or give their approval, so thank you for your time!

safe radishBOT
#

@earnest mirage Has your question been resolved?

#
Channel closed

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#
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lean otter
#

is there a way to simplify general solutions for linear diophantine equations? when finding a solution, using the euclidian algorithm is kinda annoying sometimes as it gives rise to larger numbers, which create problems when dealing with stuff like finding the smallest positive integer solution,

for example i was doing this problem:
Mr smith cashed in a cheque in a bank, the teller mistook the number of cents for number of dollars and vice versa. Unaware of this, he spent 68 cents and then noticed that he had twice the amount of the original cheque. determine the smallest value the cheque couldve been written

let x=$, y=¢, then i got the general solution as x=2254-98t and y=4554-199t, which is pretty much impossible to do cuz there is a solution but its from a non integer value of t which is impossible to guess

quasi bison
#

wdym non integer value of t

#

can you show all your work please

lean otter
quasi bison
#

if you can't get this with integer t then your general solution must not be as general as you claim

#

so you must have screwed up somewhere

#

but diagnosis requires seeing all of your work laid out clearly

lean otter