#help-26
1 messages · Page 220 of 1
so if you find one of the two angles between the two normal vectors then you find one of the two angles between the planes
and the other one is just the supplement of that
Something like this
Imagine tilting both of the arrows at the same time to the left
This is what I was describing
Both are offset by 90° so they will lie flat in the planes at the same time
I do understand everything you just said... but i still have a problem with the proof that the angles are equal... heres a demonstration of my concern
i didn't claim they're equal, i said they are supplementary
but the point is that there is a pair of supplementary angles between the two planes, and also a pair of supplementary angles between the normal vectors
may i ask for the defination of the word supplementary
and the |cos()| of any two supplementary angles are equal
so thats why we use doty product with | | to evaluate the angle
lovely.
we would use absolute value if you want to only get the acute angle, yes
well thats one part the teacher explained that we always use the smaller one. we can use the other one but we dont.
well yes everything makes sense now
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Part b)
How do i integrate 1/(x-1)^2
man
yes
(reverse) power rule (with trivial application of chain rule)
How
assum x+1 = a
Its confusing me
integrate it for a^-2 da
Why
if you're struggling with what you currently have
doing a substitution can get you something you may be more comfortable with
doom um no offense but do you have an general idea abt integration? the question in part a looks like a algebra one
are you doing precalc rn?
yes
leave it for later
partial fractions is a technique in integration
there are a few rules you need to know
the person who made it probably included it by mistake
dw about it
This is my work
you're missing like 3 pairs of brackets in this one
ln( (2x+3)/(x-1) )
none of these are droppable
excuse me
im sorry
Im not used to typing yet
I normally do it on paper
no real need to combine them yet
but anyway, lets focus on
$$\int_2^a \frac{1}{(x-1)^2}\dd{x}$$
Dx
ραμOmeganato5
would you know how to integrate something like
$$\int \frac{1}{x^2} \dd{x}$$
ραμOmeganato5
lnx^2/2x i think
kinda
-1/3 x^-3
no
no
doom
Yes
do you know what the derivative of x^n is?
in the question what do you diffrentiate to get 1/(x-1)^2?
basically d/da (A) = 1/(x-1)^2 solve for a
hello::
yes
yes
i mean yea but it skipped some steps but whatever
ok doom since you are given a and 2 as your limits you can subsitute them
no you cannot
you cant just integrate 1/(x-1)^2
why not 🙁
I swear when ever i type I keep missing few words
wait
if you keep the same bounds there is no issue here
you telling me
if I say x-1 = a and integrate a from 2 to 3 I cant use the same bounds????
the bounds are 1 lower
the application of chain rule is simple enough here that you don't need to explicitly go through that whole substitution process

I would just use that rule for multipication
there was no sub, there is no need to change the bounds
I might be wrong tho
Is this good
yes it is
seems ok, also that ln(1) is simply 0
now just simplify into ln d and c
yea
How
ln(a) + ln(b) = ln(ab)
combine logs with sum/difference → product/quotient laws
Oh yeah forgot that rule
ln(a) - ln(b) = ln(a/b)
I dont think the last equality holds. You dont need to sub x-1 back in, since you’ve changed the limits already
oh yeeeaaaaa forgot about that
ok sry then i was dumb
Np
Is it good
looks good
Wait but in the question it says c + ln d and i have that extra +1
it is included in c
the whole -1/(a-1) + 1 will be the c
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im stuck
i think you have come here with this question before and we concluded you didn't know anything about complex numbers
have you learned anything about those since then?
how do u even remember all that 😭
dunno, it stood out in my memory. but it was also only 5 days ago.
i tried replacing i with +1 and then got 2 in the denominator then 2 got cancelled and i got left with 3i
oh
it isn't a real number
so what should i do
ok so let's maybe go over some basics
do you know how to add or subtract complex numbers
yes
and multiply?
ok let's set this one aside for a bit
cause you do need to know how to multiply complex numbers before learning to divide them
i would like you to try your hand at multiplying these complex numbers:
(3+2i) * (7+i)
alr
[we will get back to your original question later! this one is simply to check what you do and don't know]
i am also gonna disappear in 20 min due to an appointment so would like to make it quick if we can.
so far so good, now remember i^2 = -1.
complete the last simplification step
5 is the ans ?
how did that all get down to just 5
alr
i didn't name myself after her, no.
@simple canopy btw when i say show your work i mean show your work
i don't mean go and redo the thing again and hope the answer will stick this time
ya i was in laptop now switching to phone to send u
i = 19-17
wtf is this
i isn't an unknown to solve for, it is the imaginary unit.
19+17i is your final answer
Yeah it is undefined
√-1?
oh
sure.
so i was doing it right
you were but then your last 2 lines were bs
Yeah, √-1 do = I but instead of that we don't know the value of √-1
anyway here. practice MULTIPLYING complex numbers. then watch this vid. https://youtu.be/EfRRpVB62Ko
This algebra video tutorial explains how to divide complex numbers as well as simplifying complex numbers in the process. It includes dividing complex numbers with square roots and radicals as well as dividing complex numbers in standard form. This video contains plenty of examples and practice problems.
Complex Numbers - Free Formula Sheet: ...
i didnt know that we dont have to further solve it
i is its own thing. stop trying to paint it as "unknown". it is its own thing, not equal to any real number, but also not some foggy "unknown".
that view is very unhelpful when working with complex numbers.
thanks ann u are a huge help everytime
Genius
well $i \not = -1$
Kaladin.
btw
so i is just i right ?
yes
Yeah you are saying true, √-1 has no value as a real unit that's why it is imaginary and that's what I was trying to say, just wording was wrong.
your wording was wrong enough that i spoke out against it.
Thanks for pointing out
even after learning to multiply and divide complex numbers how am i gonna do this
well the first half of the question just asks you to work out a itself
and name its real part and imaginary part
whats a conjugate ?
for a complex number x+iy the conjugate is x-iy
i.e. to get the conjugate of a complex number you flip only its imaginary component
the opposite ?
I meant that i is a whole new concept instead of just real numbers and that also means that "we can't put it in a real value " that's what I meant but it's just obvious
no.
the conjugate of 4+20i is 4-20i
the opposite of 4+20i is -4-20i
yeah right
idk if that was meant literally or in a sarcastic way.
real way
be careful with SPECIFICALLY the phrase "yeah right". like those words in that order.
ppl may misunderstand you.
Ann am I following right?
mhm
sure. i think the time for yapping is over though.
ive given op instructions on what to do next on his own
I did something wrong for what you called an op for?
im closing the channel now guys thank u all
?? no
OP means original poster
Sry for disturbance if I did.
that's ouchyaar in this case
.close
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I've been given the following f(f(x)-2y) = 2x-3y+f(f(y)-x) for x,y real. I've been able to prove bijectivity of f but nothing more comes to my mind, i don't want the answer, only a path to continue searching. Thank you
The question is to prove f is bijective ? Do we know if it’s continuous ?
no the question is to find all functions f which respect this equation
it's not given continuous but it may be
Also i saw that f(x) = x + b for some constant b is a valid solution
Kawachi
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Ok
Pas mal
Tu peux t’arranger pour simplifier l’expression en prenant 2x -3y = 0
Tu choisis un y tel que l’égalité au dessus marche
Ca te simplifie le truc
oui ca va donner un truc que je pourrais simplifier dans l'équation initiale
mais ca donne f(3/2x) = f(x) - 1/2
et avec ça je n'ai pas su avancer
Let $P(x,y)$, l'assertion donnée.
Let $t \in R $ $$P(f(y)-t,y) \equiv f(f(f(y)-t)-2y)=2f(y)-2t-3y+f(t)$$
$$P(2y, f(y)-t) \equiv f(f(2y)-2f(y)+2t)) = 4y-3f(y)+3t+f(f(f(y)-t)-2y)$$
There's an equal term, so we get $$2f(y)-2t-3y+f(t) = f(f(2y)-2f(y)+2t)) - 4y+3f(y)-3t$$
$$\Leftrightarrow f(f(2y)-2f(y)+2t)) = y+f(t)-f(y)+t$$
taking $y=t$ : $$f(f(2y)-2f(y)+2y)) = 2y$$
So, $f$ est surjective.
Suppose $u\neq v$ such that $f(u) = f(v) $ then
$$P(u,y) = P(v,y)$$
$$\Leftrightarrow 2u+f(f(y)-u)=2v+f(f(y)-v)$$
by surjectiviy, there exists $y$ such that $f(y) = u+v$
We get $$2u+f(v)=2v+f(u) \implies u = v$$
So f is bijective
Kawachi
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<@&286206848099549185>
Yes?
I'm asking for solving in f the functional equation f(f(x)-2y) = 2x-3y+f(f(y)-x) for x,y real which I've proved bijectivity
is it even the good channel to post this ?
If f is continuous the solution is easy. But are you sure continuity is not a given ?
yes i'm sure it's not given
Then perhaps we should prove it separately
and showing continuity is difficult or impossible so there has to be another way
uh showing continuity ?
\R isnt defined in your preamble, go DM the bot to modify their shortcut command to \R
Dm the bot ?
that means to message the texit bot, here
try sending ,help
or ,preamble
dont do it directly on this channel though, fixing the \R isnt that related to the problem
ok but still, nobody has ideas ?
I got something else when I tried to get this
instead I got f(3t) - f(2t) = t, or f(3/2 x) = f(x) + x/2
my mistake what you got is true i flipped the sign
you can then rewrite it to look like this
so we know that, for powers of 3/2, the slope between the points is always 1
from this you can try out f(x) = x + g(x)
yes yes it gives $g(\frac{3t}{2})=g(t)$ for all real $t$ but sadly without continuity you go nowhere
Kawachi
I also got g(g(x) - x) = g(g(x))
g(x) does not need to be injective and does not need to be surjective, since g(x) = 0 is a valid solution (since f(x) = x is a valid solution)
yupp i totally agree and if you try f(x) = x + b is valid
so we're left either to prove g is constant which i think is impossible
otherwise prove f(x) = x + t in another way
@real kiln Has your question been resolved?
@real kiln Has your question been resolved?
@real kiln Has your question been resolved?
I think considering ||P(f(x),x)||, ||P(x,0)||, ||P(f(0)-x,0)|| might work
It may helps but i don't know how
if i state f(0) = a i got
- $$f(f(f(x)-2x) = 2f(x)-3x+a$$
Kawachi
- $$f(f(x)) = 2x+ f(a-x)$$
Kawachi
3.$$f(f(a-x) = 2a-2x + f(x) $$
Kawachi
oh man i think you got this
Oh yeay it was clever
i'm able to solve this now thanks to you
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Can I have a starting point for this problem?
diagram
Any hints
can you try showing that H lies on MC and BN?
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wait
hold on
Im DUMB
just prove p1=p2 powers of each
then the chord is radical axis
@limber halo
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i got
f(x) = cos(arctanx - arccot x)
which i wrote as sin(pi/2+arctanx-arccotx) = sin(2arctanx)
but i seem to be missing a (-) sign somewhere?
cause my integration is supposed to give -arctanx+c
but its giving arctanx
What's the question?
find y(-sqrt(3))
Miyagi
which -ve sign?
^
I got $f(x) = \frac{2x}{1 + x^2}$
Miyagi
In the book?
oh u mean the original f(x)
What do you mean mate
yeah that is correct
now put it in the differential eqn
and tell what u get pls
How about you do it yourself
I already have my answer but you're the one doing the question
i told you the only problem i had was with the - sign
sure, but since you're the one who posted the question and are going to have to do the working out anyways, you might as well get on with it
but i did the working out
Then show it here
and i had an error in one of the steps
bro i wrote it out ...
what more do u want
That working is not going to help you
Then you should phrase this out better
and why not?
Because its gibberish
how exactly should i have phrased it?
"Okay, but I did put this into the DE, and still had this problem - [PROBLEM]; any hints?"
its not, it almost got me to the answer except without a - sign
Verbs without a subject in English come off as instructions, which in certain settings are rude, to say the least, if not properly used
$f(x) = \frac{2x}{1+x^2} \
\frac{dy}{dx} = \frac{1}{2} \frac{d}{dx} \sin^{-1} {f(x)}$
but i dont want to put whatever function he got, i wanted help with my work
You just have to solve for y mate
yes, im off by a - sign again
Miyagi
To be honest I don't know where they got that negative sign from
I'd like to point out that this isn't even much of a DE, since you can just integrate this
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why is it specifically x-a, is it because were shifting the graph p(x) by a?
cause of the approximation about 0, it makes sense
but say now we do approximation about p(x-a) what does that change?
approximating f(x) around a is the same as approximating f(x-a) around 0
oh so were just shifting the grpah back to the orgin
then carrying it out
Ohh i see
why is it x-a and not x+a ?
For the most part, convention.
This is not your thread
lmao
yk if we were to not shift it back to 0
how would the eq look liff
it would be f(x-a) = ...
but have f(a)
?
for the derivative points
If you don't shift it back to 0 then the approximation doesn't work
actually let's redo it. so let's define $g(x) = f(x + a)$. so $g(0) = f(a)$ and so on. then
[ g(x) \approx g(0) + g'(0)(x) + \frac{g''(0)}{2}x^2 ]
then since $f(x) = g(x-a)$ we have
[ f(x) \approx g(0) + g'(0) (x-a) + \frac{g''(0)}{2}(x-a)^2 ]
then replacing $g(0) = f(a)$, $g'(0) = f'(a)$, $g''(0) = f''(a)$:
[ f(x) \approx f(a) + f'(a) (x-a) + \frac{f''(a)}{2}(x-a)^2 ]
κλαουντ ☁ (cloud)
The idea behind taylor series is that a function $f$ with infinitely many non-zero derivatives (for example, trigonometric functions) can be represented as the sum of an infinite polynomial,
$$f(x) = \sum_{n = 0}^{\infty} \frac{f^{(n)}(a)}{n!} \cdot (x - a)^n$$
where $f^{(n)}$ is the nth derivative of the function $f$.
We take the first 3 terms of this series to reach the approximation you're seeing
this makes alot more sense now
ty
yea, what i was confused with was when it wasnt centred at 0
but we want to always try and shift it
so that it is
?
calm ty guys
@topaz onyx
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how should I approach this integral?
Médicis
you’re welcome haha
howd u figure out it u should be 1/x?
My first thought was that e^1/x is hard to integrate so you better simplify it to e^u
My second thought was that by u-substitution the 1/x^2 would get cancelled out, so that would give you the neat answer
well played!
i'll take it that i got it right and i did my math legally
hum
isn’t the answer A ?
show me your calculations pls
OH MY DAYS I FORGOT A NEGATIVE
yeah since the function is positive on R+ you couldn’t have gotten a negative result (1-e)
i forgot a negative and that derailed me to get C
well played
@pure talon Has your question been resolved?
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hi, can some explain to me how the denominator breaks down? i'm not getting it
$(a^2 +a^2 \tan^2 \theta)^{3/2}=\left[a^2 (1+\tan^2 \theta) \right]^{3/2}$
Civil Service Pigeon
$=(a^2)^{3/2} (1+\tan^2 \theta)^{3/2}$
Civil Service Pigeon
$=a^{2(3/2)} (1+\tan^2 \theta)^{3/2}$
Civil Service Pigeon
$=a^3 (1+\tan^2 \theta)^{3/2}$
Civil Service Pigeon
where here we used $(x^a)^b=x^{ab}$
Civil Service Pigeon
THANK YOU SO MUCH!!! ❤️ 🙏🏻
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what is the level curve related to exact equations in ODE?
and is it like really importatnt to understand further concepts in ODE
this is pretty much all the context i have
@royal sky Has your question been resolved?
given a constant c, a level curve (corresponding to c) of a two variable function f is the set of inputs (x, y) for which f(x, y) = c.
an ODE of the form M(x, y) + N(x, y)y' = 0 is exact if you can find a potential function f satisfying f_x = M(x, y) and f_y = N(x, y). in that case, you can write the ODE as f_x + f_y y' = 0. considering y as a function of x, this equation is equivalent to the equation d/dx f(x, y(x)) = 0 by the (multivariate) chain rule, so f(x, y(x)) = c for some constant c. but this is precisely a level curve of f!! so in other words, the solutions to an exact ODE are given implicitly as the level curves of the potential function 
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can someone explain the Rtu thing
have you been helped
?
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.
@north heath Has your question been resolved?
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✅
how did this triangle on a u t graph appear
thats the question
@north heath Has your question been resolved?
t goes from 0 to M
u goes from 0 to t
yes but whats that got to do with a triangle
this is a double integral so its calculating volume
that shape is a triangle
the shape is an area
and where is the function
single integral calculating area integrates over a line segment
so the function is on the 3d space that is inside the triangle cordinates for any z
the graph is only the domain of integration
well if it was
exactly
how would it look like
this looks like its from proofwiki
just use any functions you want
on a line segment it would be something like this on the line ab
yes exactly
if we have a function on that triangle how would this space we calculate look like
can you make a graph where i can see the S same as here for that
ok do that
is this the Laplace transform of a convolution?
it is
did i write the page? lol i might have, i used to write for the wiki
but this is probably prime mover
yeah he did it for this
anyway, not relevant
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simple math question for a distribution is -F(x-l) *(-x+l) = F(x-l)**2
$-F(x-l)\times (-x + l) = F(x-l)^2$?
This is sad 😢
@void rune Is this your question?
yes
Yes, assuming F is a value or a variable, and not a function
yes F is a variable thx !
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can someone explain to me why this diverges
.solved
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hi
i need help understanding this question
hi
yoo
whats good
whats the difference between a quadric surface/ cylinder and a surface of revolution
<@&286206848099549185>
I’m not too experienced in these types of problems but here’s my guess, it may help. A quadratic surface is figure that is graphed by a parabola or something. A surface of revolution is a function that is rotated about a point to create a figure.
@neon iron Has your question been resolved?
technically, cylinder = solid cylinder, which you cannot really create by revolving a function. (bonus question: why?)
a hollow cylinder without "lids", however, are also surfaces of revolution. some shapes and surfaces, such as an ellipsoid, are also surfaces of revolution.
however, every possible surface cannot be created by revolving a function. (e.g. a hyperbolic paraboloid or "pringle" shape, or an elliptic paraboloid)
so some quadric surfaces are solids of revolution, but not all. and of course, all solids of revolution are not inherently quadric
so the surfaces of revolutions that are rotated have their equations constructed from a generating curve radius function?
yes. there's a generating "radius function," as you aptly put it, and that's revolved to create the surface
though this generally doesn't give you an implicit equation for the surface
but are their general equations formed that way?
in practice, not really. the main "application" of a solid of revolution is finding its volume by integrating something based on the "radius function"
(in this case, you have an 'inner' and 'outer' radius to give the shape some thickness)
in theory, you could possibly find a parametrization of the shape, especially in spherical/cylindrical coordinates oriented along the axis of rotation. but whether that leads to a clean implicit surface, i'm not sure (i doubt it)
i see, also
a trace of a surface is where the surface intersects the planes right
what do they mean by the coordinates of the focus
the idea is, assume that the intersection of this surface and the plane looks like a parabola (because it does). what's the coordinate of the vertex of this parabola?
i.e. focus = vertex
so whats up with the y = 5 and x = 2
well, those are the planes you are intersecting with
so you have 2 equations:
\begin{align}
\frac 12 x^2 + \frac 14 y^2 &= z \
y &= 5
\end{align}
and both must be true at the same time
χασιβ ♥
think like a system of equations, but instead of a point of intersection, you're now getting an equation of intersection
but theyre giving me certain planes
and when finding intersects i would set 2 variables = 0
yeah this will be different to traces
but you can eliminate one variable here (you should expect to get 2, since you need 2 to define a parabola)
any guesses as to which one?
wait i thought traces are when the shape intersects the axes themselves
when the generating curve lies on the axes
is that not?
well
i think when y = 5 the shape is up right
shifted up?
thats what i assume
wso the center is y =7
i mean 5
<@&286206848099549185>
im guessing you meant "plane passing through an axis," and not always. generally we define 'trace' to be an intersection with a parallel plane to y=0,z=0, or x=0, such as y=5
not necessarily. the shape could change between 0 and 5
you can only assume that if the shape is constant between 0 and 5, in this case it's a different parabola
im talking about the generating curve
i thought the trace was this
@patent owl this is what i mean, is this what the question is asking for ?
i dont understand tbh
i know they want this intersection
its not always a "generating curve," because the solid is not always a solid of revolution
which is why i wouldn't think of it like a trace at all, really
but if you want to, just set y=5 instead of y=0
you'll note that this is the same thing as subbing equation 2 (y=5) into equation 1 and "solving" for a parabola
so there's a few ways to think about this
@neon iron Has your question been resolved?
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Exo 5 eq2
what happened to the -1 on the left
looks right but
whats the second part of the question?
"and...."
"solve the following equatiuons and.."
ah
also do you need to present a domain for x?
then x is greater than or equal to 1/2
Square root thing
right
unless youre dealing with complex numbers which i doubt
this is real analysis right
not that im experienced in the field but i doubt complex numbers would be involved in a RA class right
The module has both real and complex numbers
But in this chapter it's only real numbers
So S=[1/2,+inf[?
@neon iron just to make sure
yeah mb i got a little distracted
its ok
yeah but for the infinity end point you cant have a square bracket
[ ] means include the endpoints
() means dont include the endpoints
can you ever include infinity?
whats infinity
so [1/2,+inf)?
do you think it can be -inf?
im confused
in class the prof usually uses [] to include/not include endpoints
did he ever use ] on infinity?
or she
im not saying you cant use ] ever
huh...
different education systems maybe?
does the symboles change overtime
do highschool students and uni students use the same symboles to include and not include end points?
well as far as i know its a matter of convinient notation, i dont see inf being includes in the domain
cause think about it
whats infinity
when you "include" infinity by writing ]
what are you including?
you arent reaching any number it just keeps increasing
its a notation convinience thing
and an intuitive thing too now that i think about it
ok so theoratically lets say we're not including a real number like 12
so i dont think its universally correct to use ] in inf
brother just note that the square brackets go in this order []
itll be this
youre including 1/2 and values all up until 5 but not 5
so you can include 4.9999
for example
so its gonna be [1/2, 5)?
my bad i came up with my own example in my head of [1/2, 5) and therefore mentioned 5
i just forgot to mention the example
for my example yes
ok
in your case you arent including 12, so itll be all numbers approaching 12 but not 12
i understand what you're saying
i think the symboles differ in each country
i'll go ask the prof tomorrow
maybe he was wrong
maybe he wasnt
but i understand your point in here
@neon iron after some research
it appears that we were both right
this is the european way of writing intervals
yours is the standard one
😂
interesting
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Yaah
He hates you less (your teacher)
if l and m are parallel what is x
lol
This is easy too
i think you got the idea right but the math wrong anyways
yes
this
In the diagram below, AD is perpendicular to BC and DE is parallel to CA. If ∠BCA = 68◦,
find ∠ADE, in degrees
similar triangles?
oh yeah, nevermind
didnt understand the idea for a sec
ok
Yeah, basically, BE is colinear to AB (in fact, its a part of it) and DE and AC are similar.
ye
So they fit the criteria for being similar triangles
Nope, consider the 90 degree you got near it
yep
so 22
In triangle ABC, AB = AC. Let D be a point on side AC such that AD = BD. If ∠DBC = 66◦,
then find ∠BAC, in degrees.
isocelese triangle so
hmm how do i do this
wha
Do sum of angles in ABC
What is y
hmm
ABC is isocèles
Yes I didn’t check the math. But should be yeah
ok
Test it
i have a darn pdf this week
let me get online
ok
yea
ima ask him
In the diagram, BC is parallel to DE. If BD = 2, BC = 12, and DE = 21, then find AD.
set up an equation
AB = x
(2+x)/21=x/12
x=24/9?
or 8/3
so in total 14/3
i think
correct
lol
im 1/2 done
In triangle ABC, ∠ABC = 90◦. Points P and Q are on side AB so that AP = PQ = QB, and
CP = 7 and CQ = 5. Find BC
hmm
AC is 9 or smth?
BC is 3???
Where did you get that
i got QB as root(8)
1st thing that came to my mind
Yeah that's right
ok
This's right
do BC is
Seems true
Yeah
ok
In triangle ABC, M is the midpoint of AB, N is the midpoint of AC, and G is the
intersection of BN and CM. The area of triangle GMN is 6. Find the area of triangle GBC
the two triangles are similar
Yeah
I don't think it's 12
oh
24
dam
Mannnn
Not 12
nosolsssssss
.nosols

!nosols
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.
Ok ok
YES I GOT IT IM HIM
Think about the height of each triangle
and height ratio is 1/2
What are you talking about
GMN and GBC are similar
number 10
With a ratio of 1/2
Ohhh
Meaning the ratio between their areas is 1/4
oh shoot
i realized there is a second page ☠️☠️⚰️⚰️😭😭💀💀✌️✌️
quesitons look ez
like that asks for degree ABC
Let A, B, C, and D be four consecutive vertices of a regular nonagon. Two of the sides are
extended to meet at P, as shown below. Find the degree measure of ∠ABC
isn't that just 140
yea
So what's P even used for
next question
Using the same diagram as in Problem 14, find the degree measure of ∠APD.
Peepee
lol
how do you find APD
its a pentagon
so angles add to 540
BAD and CAP are 40 each
Bad boy likes to cap
long DCB and long CBA are both 220
so APD is 20
What ! 😂
kinda weird lol
Me or the 20 ?
no
The area ?
yea
I’m not sure .. I never do the math
Remind me of what we know
oh
for that
GBC is 24
and GMN is 6
fot this DPA is 20

Are you asking me to check ?
WAT
wah
I never do the math let’s try it another way
Look at triangle OND
NOD is 90
OND is 140/2 =70
no
its a pentagon
so angles add to 540
BAD and CAP are 40 each
Bad boy likes to cap
long DCB and long CBA are both 220
so APD is 20
ok
we have to find ABC
I need to get a beer
wha
Ok can we call MNG = X
ok
X is the area of MNG ok ?
ye so its 6
Do you agree that MNB = 2 MBC ?
mhmm
Same height , basis x2
yea
So 6 + MGB = 2(24+ MGB)
I just split the areas in this equation
I just split the areas here
Wait
The 2 here should be on the other side !
It’s MBC = 2 MNB
oh lol
Now split each of them to find MGB
Ok now do you agree that MNB = MNC
So that means that : MGB = NGC
yea
Cause they share MGN