#precalculus
1 messages · Page 201 of 1
nice
because its abstract
i just think its poorly presented and taught
its really not that hard though when i reach out to other people except for my teacher
nobody easily transitions into thinking in radians and ratios
none of the notes in class are related to the homework
lol
half of my class was in tutoring yesterday LOL
LOL i should
i usually try to do stuff with the tutors first before i come onto disocrd
oh lemme add
our quizzess/tests/hw are graded all or nothing
partial credit nonexistent 
what? How does that work? Miss a minus sign and instant 0 on the entire assignment?
at some point y'all could teach each other
Could somebody help me to figure out the steps for simplifying these trig functions with trig identities?
I am stuck on figuring out number 17
There is an answer key
I am having trouble figuring out what identities I could use because there is no Pythagorean trig identity for tangent and cotangent
what's happening from your first to second line?
it looks like you squared it properly and then completely wrecked it
I expanded it and I thought I could factor out tan n from the rest of the expression
but cot^2(n) doesn't have a factor of tan(n)
do you know the relation between tan and cot?
They’re reciprocals if each other
1
Wait don’t you mean cot^(n)
yeh
Not cos
typo
Ok
So now would I just break up tan^2(n) and cot^2(n) into sin(n)/cos(n) for tangent and cos(n)/sin(n) for cotangent and then multiply by the LCD?
no
note that 2 = 1 + 1
and you can apply the identity used in Q14
identities relating tan to sec and cot to cosec come from dividing both sides of
sin^2(x) + cos^2(x) = 1
by cos^2(x) and sin^2(x) respectively
cancel lines on the 1s look like xs
Oh I see that lol
its pretty obvious that - 1 + 2 - 1 = 0
so you don't really need to indicate that's what you're doing
(also your variable n changed to t)
$\log(a^b)\equiv b\log(a)$
RokettoJanpu:
but you are multiplying the value of ln(t) by 9t^8 I don't understand, you can just have the value go back inside the log after you multiply it? how does that work then
how do I know what b is?
you have 9t^8 outside the log, but it seems that you've left the t^8 outside the log and only "brought" in the 9
so it's just because the constant can go wherever essentially
?
it just reattached to the ln to use that property?
no you can bring in t^8 too, your book just chose not to do that
sure
np 
ig for the problem it makes sense they only take the 9, as the rest factors out nicely then
7
"x^2 <-1"
think about what that means in terms of absolute values

oh..
surely what you have now is < 7 no?
oh wait
these inequalities are flipped

which is even more interesting
a number greater than 7 but less than -7

ok so I understand why the -1 doesn't work out now, but refresh my memory for the uh part here
x^2 > 13
this becomes x > sqrt 13 right?
there's an extra -sqrt13 > x ?
yes
graphically
you can look at how the parabola looks
also you really need to split those inequalities
it makes no sense to combine them
right that's true and makes sense, now i got the proper form i was clueless
-7 > x^2 - 6 > 7 makes no sense
ye lol
x^2 > 13
becomes
x > sqrt13 and -sqrt 13 > x
yep
that makes sense
what is r?
radius
radius of what
to find six functions
just draw a triangle
i remember seeing some stuff like r before, but my teacher told me to say f that stuff
yes
ye sec and cos are reciprocal
same with sin and csc
and cot and tan
pretty much by definition
u know what quadrant it's in right @elfin birch
no
oh wait
i think it's cuz of cot < 0 and your sec is positive which means cos is also positive
i mean
so it would be in 2
you're not wrong
i think 4 is right
just reasoning wise
since cot is neg given and sec (1/cos) is positive it has to be quad 4
this is one of the mnemonics i dislike
ahh ok
😦 it's one that helps me remember @clever inlet do u use anythin to remember it?
cos(t) gives the x coordinate on the unit circle
when you have an angle of t from the positive x axis
sin(t) gives the y coordinate
in quadrant 1, clearly x and y coordinates are all positive
and consequently y/x will also be positive
that makes a fkton of sense
hence sin(t) is positive
cos(t) is negative
for t between pi/2 and pi
and the ratio y/x would be negative
you can figure out the rest
yeah i never thought about it like that it makes a ton of sense
cause most teachers make you memorise dumb mnemonics
without actually making you understand
cos is x sin is y, gona be positive at quad 1 all the time, goes for the same shit for the other 3 in opposite ways
yeah i dont know jack nobody teaches me concepts only memorize stuff and now im basically 20 IQ
thx man
😄
so when it comes down to something like this and it asks you to find Domain and Range
since it's abs (2 + 7x)
the domain is -inf to inf because there's no fkery but
the range is [0,infinity) because it's an abs value and can't be less than 0?
i see
hmm in that case it would be
domain: (-inf,inf)
and range: (-inf,inf)?
cuz of the x^2 making it impossible to be negative
wait no it'd be [1,inf)
for what?
yeah im talking about the range
rip discord
apparently it's still [0,inf)
it should be [1, inf)
mathway.com be bugging then
ima check wolfram alpha
wolfram alpha is right ur right [1,inf)
mathway.com buggin smh :p
|x^2 + 1| = x^2 + 1 for all real x
yeah and when x is 0 , 0 + 1 = 1 so min has to be [1,inf) mathway just not perfect
dam discord!
i can see it
oh 😮
oh gotcha
are you having any issues with that question?
so how exactly are you supposed to be envisioning this
7x^3
7 is positive
x if it's negative makes the equation negative right?
if it's positive the whole thing is still positive
firstly, there's a trick with polynomials
but
let's do the proper way first
you're right with that
so consider f(-x)
7(-1)^3 = 7(-1) = -7
7(-x)^3 = 7(-x) = -7x^3 right
gotcha
= -f(x) right?
oh shit
which is the definition of odd
right there's that whole thing with them
for polynomials there's a trick
but i'll let you figure it out
well
"trick"
more of an observation
completely forgot how i was supposed to do that, i was trying to picture how im supposed to envision a full grpah in my brain
graphically, they're different types of symmetry
anyone know how i can answer this?
what have you tried
following the sequence in the textbook. I reflect y=√x in the x-axis, and shift it to the left by the units of a
but doesnt the answer actually shift it to the right? Is it the sequence thats wrong?
It's just a reflection across y=a/2
im not exactly sure what it's telling me to do
am i supposed to subtract the values
ah.. ok i got it thanks
so -x^2 -8x -3
I gotta make it a quadratic equation first, I assume negative is a no no
x^2 + 8x + 3
to complete the square I do
(b/2)^2
this makes new equation x^2 + 8x + 16 + 3?
er.. hm
then it's (x+4)^2 +3 ?
idk probably
amen
ok i figured it out, i gotta look ta the (x+4) thing and solve it x = -4, and then substitute -4 as x in the original equation to get that shit, that being said..
why is this a minimum, im stupid
x^2 - 14x + 51
x^2 -14x + 49
(x-7)^2
f(7) = 49 + 51 -98 = 2
you're able to find the location of the vertex but you don't seem to be completing the square properly
😮
eg for the previous question
-x^2 -8x -3 = - (x^2 + 8x + 3)
you can't just add 16 inside those parentheses as it changes its value
but you can do + 16 - 16
hm i see so
-x^2 - 8x -3 = -(x^2 + 8x + 3)
Complete square
x^2 + 8x + 16 -16 + 3
(x+4)^2 -16 + 3
(x+4)^2 - 13 ?
don't forget that you still have the - at the front
(that will distribute to both terms)
hmm wait so would that make it
-(x^2+8x+16) -16 + 3
or would i have to keep the -16 inside the parentheses
wait no
-(x^2+8x+16-16+3)
yes, those would be inside
-((x+4)^2-16+3)
-((x+4)^2 -13)
ok thanks i think i understand the proper equation like equalization or whatever the term is now
but any idea on why the other question is am inimum
distribute the - sign
then consider the value of -(x+4)^2
oh wait there's more to this one?
-(x+4)^2 + 13
oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooh my god
it makes sense
wait what the heck, is the y intercept the answer?
no
in use atm
im learning propotions even tho im grade 6 and this is like grade 8 or somethingn math
isnt the answer the bottom of the parabola iirc
bottom of the parabola? was i supposed to graph
no
A basket contains only apples and oranges, and the tatio of apples to oranges is 9:7. IF there are 128 pieces of fruit in the basket, how many oranges?
b-but conceptually thats the minunum
Can someone help? its my first time
why do you think its the y-int?
and can you tell me how you did it
@uncut mulch it seems it was coincidence i think cuz when i apply
-4 into the equation
-x^2 -8x -3
-16 + 32 - 3 = 13
ratio of apples to oranges is 9:7
128 pieces of fruit
@wide lagoon Read the rules in #❓how-to-get-help please
Oh sorry xD
apples is 72 oranges is 56
but that isn't the y-intercept
y-intercept occurs when x=0
Thanks wrong i think
ah! that's true wait.. then -(x+4)^2 + 13
Yea that is
in the vertex form:
y = a(x -h)^2 + k
k is the value of the y-coordinate of the vertex
so y = -1 (a) (x-(-4) (h) ^2 + 13 (k)
so 13 is k
ohhhhhhh
@uncut mulch u make a lot of sense my friend thank you
@wide lagoon A basket contains only apples and oranges, and the tatio of apples to oranges is 9:7. IF there are 128 pieces of fruit in the basket, how many oranges?
hm 9:7
8:8 = 64 each
1/8 of 64 = 8
are u sure it's not 64-8 = 56 oranges
sure
In a certain system of gears, the ratio of the number of teeth on the first gear to the number of teeth on the second gear is 7:3. If the first gear has 259 teeth, how many teeth does the second gear have?
nice it worked out
But how do i do the orange one
yeah i dont know the formula i never learned it i just do random stuff like what i said earlier, do u have to submit it online or via paper?
do u use webassign or something like that
IRL
ah ok 😦 sorry i dont know
kk
back when i had to do that stuff i would use what i said
i mean im in grade 6
this is like grade 8 or somethijng
firs ttime learning it lol
yeah ik what u mean my teachers didnt teach me like concepts really well i just had to wing it
9n : 7n
9n + 7n = 16n = 128
i mean i have sat school
😮
ramonov just answered it for u
9n is apple 7n is orange
that would be an idea of where to start
56?
9n and 7n represent the number of apples and oranges
and they are still in the ratio 9:7
nice
So N is 8?
lowercase n but yes
possible to show me how?
16n = 128
n = 128/16 (from dividing both sides by 16)
damn that's awesome
how did you get 16
9n + 7n
9n and 7n represent the number of apples and oranges
and they are still in the ratio 9:7
their total is 9n + 7n = 16n which is also given as 128
Ahh
im lowkey losing my mind rn so im probably never gonna forget what was said today
feelsgoodman finally learning
oh crud ive hit another roadblock
y=7x^2 + 42x + 65
y=7x^2 + 42x + 441 -441 + 65
consider:
7x^2 + 42x + 65 = 7(x^2 + 6x) + 65
O_O
7x^2 + 42x +65 = 7(x^2 +6x) +65
OH GOD
7(x^2 +6x + 9 - 9) +65
7((x+3)^2 -9) +65
similar to before,
distribute the 7
so 7(x+3)^2 -63 + 65
y = a(x-h)^2 + k
y = 7(x-(-3))^2 + 2
k is 2
yes
aren't they teaching you this in class?
my situation is kind of rough, i havent done math in like 6 years and im taking calc rn so im going off of stuff from memory
ah
im sure u noticed that i confused something for the y-intercept
so u can tell that im kinda (yikes)
you'll be fine. you're getting these concepts quite quickly
hmm
er that is not what i meant in terminology
that doesn't mean what you probably think it means
yeh its not that either
oh
^
you could literally divide 7 by 2 and get 3.5 which is x^3 * sqrt(x)???
wait what O_O
if true that is some big news right there
altho it wont work to my problem i guess cuz if x^3.5 that means all real numbers would be the domain right
huh thats true
altho I guess technically speaking writing it as 3.5
is the exact equivalent as 7/2 which forces u to take
the sqrt (x^7)
but not really because thats like saying x^1/2 is for all real numbers
yeah
still issues with -ve numbers
when dividing by zero some equations just say that it equals some limit for continuity purposes
think my brain just dipped in some lava
but the meaning is ambiguous
It really doesnt save any time
+ve and -ve are generally accepted as abbreviations
Considering you have to move you hands away from the letters on the keyboard and look for the minus or plus sign
You also gotta press shift too
keypad
lol
laptop users
that probably depends on the typist's speed tho right
If you're above about maybe 30 wpm then yeah you're wasting time
I just got to this problem and i have to say, what on EARTH IS TRANSCENDENTAL BRO?
WE ENTERING LIKE 4TH DIMENSION IN MATHEMATICS OR SOME SHIT?
O_O
wtf is that question...
is it synonymous with irrational
I need to learn up definitions ASAP
because irrational is not on the list
No @viscid thistle
pretty ehh question
Irrational doesnt really apply to functions
And irrational does not mean transcendental
the answer to the problem was polynomial but reading the word transcendental spooked me
does Transcendental apply to functions either though
there's more than 1 correct answer
but polynomial is probably the one they want
i guess it depends which algebraic you mean
seems like a blanket term for non polynomial numbers
polynomials are also rational functions
that's true
Like the pythagorean constant is irrational but not transcendental
O_O
overall horrid question
I think algebraic refers to basic operations
Like excluding things like trig functions etc
Algebraic means +-×÷^ and sqrt iirc
well at least in this case its definitely none of the other 3
then surely the last one is equally as algebraic
Polynomial is the only logical answer for the last one imo
algebraic?
I mean a polynomial is algebraic in the same way a square is a rectangle
@viscid thistle ye
weird sets of questions, ive done like 9 of them mand they were all polynomials or algebraic
where's the love for rational or transcendental
Sorry, I am not here to answer the question, but I do have one, relating to this one. What does it mean for a polynomial to be transcendental?
Something like log or exp
oooohhhhhhhh
ooh
i thought transcendental was some like infinity type stuff
O_O
Specifically not being represented in a finite number of algebraic operations
so essentially not algebraic, right?
x^-1 and 1/x^-1
both of their domains are (-inf,0)U(0,inf) ?
That second equation is just x lol
ah right
0/0=1 so it's all good


Lim as x->0 x/x


You have to simplify the expression before taking the limit

Lim as x->0 tanx/x
Im telling you man 0/0 is 1
sin(x^2)/x 
1x = 2x; divide each side by x
1 = 2
thats a massif sigmy boi
Can someone create a formula for this
i wish i even knew what i was looking at LOL
LOL
Why do you have two indexes
im sorry i couldnt help it
u could tell me that's the DNA strand genome or something for coronavirus
and id believe u
Its not scary lol its just greek
yeah you gotta learn greek first
That weird E looking thing is called a sigma
it means sum
I swear im not trying to prank you
u mean like summa cum laude?
yeah
Its actually called sigma
exactly
hm sigma
it means sum
sounds a lot like ligma..
Did you guys figure it out
Its not some sort of immature joke ninja would make
I was thinking of using this
i dont understand amd is right why the fuck does it have two indexes
is it a double sum
Ok so o wanted to use the formula at the start but the thing that being multiplied if changing
So lemme get this straight
This series is
0+3+8+...
Or am i interpreting this wrong
is this a precalc question btw, cuz i think i wouldve printed this out and given it to my teacher if i saw something like it
Do you mean like the sum of a sum or something
voltage are you as bored as me
@viscid thistle yo what did u eman by like 2 index and stuff
cuz it must have taken a lto of effort to find that meme
no bro im sufferin rn
from lack of knowledge
i need like 5% of you guys combined IQ, no but real talk is that actually precalc (this number is probably like infinity)
cuz im scared for my next class if it is
wonderful
id cal that abstract art of the highets level right there
Bruh this question is kinda hard
that is much more pleasant
If you guys can solve it then can you make a more general formula?
wdym more general
And also this should have a solution
you want us to sum it?
this reminds me of like a sphinx riddle
Like use the variables instead of numbers
he means an explicit formula
that second one is literally 0 + 1 + 2
come up with an explicit formula for the first one
also why did you write B=2+3
as opposed to B=5
i presume because 2 is the same as n
the functino could be defined as a recursive relation instead of a sum 
lol
wait hold on what if i do this
i learned that in physics class
like 0 times 3 plus 4 times 1 plus 5 times 2 plus 6 times 3 and so on
yo, how is this wrong!
quadrant 1
cot = c
tan = 1/c
tan = sin/cos
cos = c?
there's a formula for summing consecutive integers
wait this is trig?
its not as simple as taking the sum of the b then multiplying it with the sum of the n
@viscid thistle I legit JUST got to that conclusion after googling
lmao
yeah it seems it's like cross mulitplication is the answer
cot(theta) = cos(theta)/sin(theta) = c/1
cos(theta) = sin(theta)*c wait nevermind u said divided by c.
yeah since we flip/invert sin/cos and mult by sin
there is definitely (?) a way without sin though
@hallow flicker i think i got it
actually maybe not
@viscid thistle ud be right, cuz it doesnt take sin going in
since inverting cot requires a periodic function
$(\frac{(z+3)^2+(z+3)}{2}-6)(\frac{z^2+z}{2})$
AMD:
sqrt((cot(theta)x)^2 + ((1/cot(theta))y)^2) = 1 and we are solving for y
good luck
my brain cells are screaming at me
where'd anime kid go
now we are speaking the same language
i got his formula
@hallow flicker yo AMD got ur form!

you could probably rearrange that by completeing the square
idk man
cot(x)=cos(x)/sin(x)
im honestly really saddened that cos(x) wasnt c
that was like a betrayal you know what i mean?
isn't it just c sin x
- multiplication?
maybe your keyboard is greek
ok
if i have to put the * and it's right im gonna have world war 3 in my brain
but i think it's saying i cant use sin
actually
cot is cos/sin, and is equal to c
cos(t) = cot(t) * 1/csc(t) right?
and then spam some pythagorean identities or something
$\cos(\theta)=\frac{c}{\sqrt{1+c^2}}$
AMD:
yay
pythagorean identities probably
no they'll just want that ratio ig
ima submit it and c
1^2=1
O_O
👀
draw a right triangle in quadrant I of the unit circle with some arbitrary angle theta
so far so good
yep yep
right
so cos theta is the horizontal part of the right triangle
(x/y)/(1 from x/y) and so we normalize x??? where x = cos idk
sin theta is the vertical part
SOH and CAH
so sin is 1 and cos is c on the triangle?
vertical is 1, horizontal is c yes
and then pythagorean 1^2 + c^2 = hyp
1 + c ^2 = hyp
and since it's asking for cos, it's c/(1+c^2) but it's sqrt cuz that was supposed to be sqrted b4
holy fuck
whats hyp
hypotenuse
oh
and fk this question lmao
i don't blame you for taking 8 attempts because it really was not a good question lmao
this discord is a blessing
yeah i also kidna double clicked
i tried a few guesses from here without reading the feedback
and it was like that one that said u cant use sin or whatever
so im like "shiiiiit"
but the homework shit is worthless in points anyway, in eed to understand what im doing and pass the exams
thanks for the help in understanding what i need to do
that's the spirit man
so many people just want the answers
and then come test time they fail miserably
if my brain could google it automatically i would just want the answers, unfortunately life ain't that gifted!
lmao
gotta understand asap
why does 1 from cot equal hyp?
?
oh
hm idk i intuitively get it
wait what
cot changes over delta but hyp is always the same?
cot = cos/sin = c/1
sin = 1 cos = c hyp = 1^2 +c^2
a^2 + b^2 = c^2
cos = c/sqrt (1 + c^2)
yo i just realized u said delta, what the hell is that
oh i meant theta
oh
but same thing
it's all greek to me
yeee boi
tiime to apply some of htat learned knowledge
so it's sqrt 24... cos should be sqrt24/5
but i just realized it says 2theta..
this isnt one of those double angle formulas or something right..
hmm
i kinda gave up on that one for now cuz of the time but
the good news is
I went further and did this one
in like 10 seconds flat
that felt good lol
alright my time limit hit, time to go back and do that problem
im supposed to find theta?
O_O w0t
cos2theta = cos^2 theta - sin^2 theta
isnt it like
Cos2theta = cos^2 theta - 1/25
Wow lol im surprised thats such a nice number
you know
im banging my head on my desk rn
cuz i actually solved this rpoblem correctly
but i didnt submit it on time by 1 second
Bruh
i shouldve avoided that meme
Which meme
somethin pregnancy or whatever
lmao
wouldve had 1 extra second of learnin
oh well good stuff tho now i know two ways
to do that problem
ye also good taht homework is kinda on the low end of the grading spec
Thats why pregnancy happens
If it weren't for mistakes humanity wouldn't exist imo
appreciate all the help im probably gonna become a regular on this discord, i didnt expect so many good people helping out maybe one day ill get to 5% of you guys level
a man can dream right?
true humanity is a mistake in of itself, but that is why it's also the paradox/contradiction of perfection
how can something so beautiful be so ugly at the same time
Imagine if your dad didnt accidentally nut inside ur mom
lowkey half of divorces that would've happened get stopped because of accidental nuts
the other half happen because of them though
Children are a blessing and a curse
You're onto something
The duality of man or some shit
now if only i could apply that to like that sigma question earlier that one guy posted
was that a precalc question
because i never seen anything like that in my entire life
whattt that was in alg 2?
Just use that brain of yours and stop going on 9gag
the truth hurts but so does not knowing math for later so ill take that advice
i hope to get more questions like that transcendental crap from before, that'd be nice
logs and exponents right
LMAO
bro women don't even fit on the equations in math dude
This is what happens to your brain when you use 9gag
sin(woman) = no sin (man)
a man without sin is equivalent to a woman with sin
this is why men go to jail over false rape accusations
thanks im a lawyer
lmao
No one will ever accuse him of rape
pence also means
the man's size is probably incapable of causing penetration
as a result even if they did accuse him, they would fall back to the same limit of which sin(women) = no sin (man)
I dont understand your logic here
that's the beauty of it
of course that is absolutely correct but it's not the women that is being talked about in the equation
it's the man
an innocent man is equivalent to a woman that has sinned infinitely
Man sins just as much as woman
!
Just in different ways
indeed
sin(aphrodite) = cos(marriage papers)
Q.E.D. = divorce
@fleet yew remember that 23/25 beautiful number
this was the next question
some scary stuff
😦 oh man
Especially in trig
how much of this do u think exists in calc
Trig stuff never goes away
damn u world!!!
u mean this ?
No that game sucks
lmfao
I didnt like it
It wont be for a long while
is it like rocket science discrete math type of stuff
man how the fk did people invent all this math bro
it's one thing to learn it, another thing to learn it without learning it
Because they were smart
they were smart, yeah right bro what kind of drugs did they shoot up into their brain bro
they were geniuses and spent their entire lives on it
archimedes probably like did a breakdance on his brain until a concussion gave him supergenius intellect
The capability of the human brain is truly amazing
it really is
What grade r you in?

Feynman himself wasn’t any genius but he was able to be a pretty good physicist.
I’m in 11th grade (USA)
Imo there is a genetic component to intelligence
i probably shouldve taken physics
whoa
u old
Nah as long as ur brain is at least average with hard work and patience u can be very good in physics
i just wanted to insult your age
how old are u @viscid thistle
so i could feel better about myself
Feynman wasn’t a genius and he became a pretty good physicist so
look fren if i told you my age then i would stop being my age
Feynman was a genius
its happened to all the ages ive been
How dare you
feynman might as well be kim jong uns 3rd brother
he has a pretty big forehead
i know that guy
if you know what i mean
Feynman was just pretty curious and interested in what he wanted to learn
I hate it when people say shit like oh albert einstein failed math class as an excuse for being dumb
yeah no he didnt fail it, he was busy nutting all over himself when he figured out e=mc^2 in 2nd grade
now if only i could solve how to rig the lottery..
Or he figured out a proof when he was a kid somethin like That idk
i hate it when my illiterate teachers say that math is bad
yeah tahts why theyre illiterate
wassup guys
My us history is so smart in historical and business stuff but he sucks at math and science
It's all the fucking liberal arts teachers all like "OMG i suck at math"
he used up his nen potential in the history but gave up on math and science
Normie teachers i swear
Ye ig
uhh well my religion teacher seems to hate math and my french teacher said that if you like conjugating verbs you must like math because you plug stuff in and then my biology teacher said that the directino of dna (antisymmetric) is very mathematical
stuff like that
bro religion?
I’m alright at history and I’m pretty good in language arts and I’m amazing in math and science
At least that’s how I rate myself
idk its what made me like math though
I love math but conjugation is retarded
I was graphing trig functions
French is the opposite of any sort of logical process
😮
bonjour
You literally just said it lol