#precalculus
1 messages · Page 164 of 1
I got 4√3 not 2√3, unlike henry @pliant pecan
12/6 is 2 tho
Yikes!
@harsh cipher
Domain: t > 0
understandable
The answer is supposed to end up as 4/3, -2/3, and 1/2
I got the -2/3 so far, but I messed up on the 1/2
And I can’t figure out what I did wrong
I’ve tried coming back to it
I still got the same thing
@barren hedge is that your handwriting in your pic
That’s my handwriting
that'd be a compliment, trust me
it's a bit hard to read with your angular and 4-like your eights are @twilit shadow
i bet you're one of those people who doesn't put a stroke on their sevens either
oh that's ok at least
I hope that’s better
oh really?? I've never done this problem in my life and I got it, I'm happy
literally never learned this, I'll send a pic
Nice
On the one you put an X on, I got the same as you there, but where did you get the one with -8 -16 -20/3 | 4/3 from?
Well, I didn’t get the top row, I have no idea where that is from
the x is crossed out, for that one what I did was just multiply the lowest row by 4/3 (so I get an 8 in the 1st column)
Okay
@barren hedge @plush trench sorry I got picked up to get food since I hadn’t eaten today
oh that's not good
can't do math(s) on an empty stomach
Wait, did you multiply by 4/3 or -4/3?
negative
Okay
just noticed I didn't write it out, I didn't think i'd get this far sorry lol.
It’s fine
I was trying to avoid fractions, but if this is how it’s solved then okay
well the answer is literally fractions
so that's how I got the idea to multiply by -(4/3)
Yeah, but I was trying to get it as late as possible
6ix, no I don't believe that is, always do common denominator
@barren hedge I did? I added 5 to top and bottom of the second fraction to make x plus two into x plus 7
gotta do it by multiplication, so a/b + c/d → ad/bd + cb/bd
Ohh... yeah, that’s seems familiar
so you'll have to distribute
Let me try it now
6ix seems to be going through quite a wide range of topics
ye lol
I’ll admit that all his problems seem fairly straight-forward, though, and that’s nice
I really dislike word problems
@twilit shadow Idk if you still want it, but here's a somewhat cleaner version.
Sorry, like I said, I’m barely coming back to math and this class is starting off by reviewing previous math courses I’ve apparently taken? Anyways, here’s what I worked out
Good, right?
I have a new problem. I have no idea where to start.
find how many units of red she uses. that must be less than or equal to 32.
What did you do at the end @pliant pecan
then find how many units of blue she uses. that must be less than or equal to 54.
both in terms of a and b, of course. @twilit shadow
Thanks
yeah I followed you to the second to last 6ix.
I think that makes a lot more sense now
@pliant pecan Did you just subtract 1x² from top and bottom? Because you can’t do that
Refresher?
@plush trench I can’t ? I took out the x^2 because it was divided by x^2
No
no, you gotta divide the numerator by the whole denominator
Rather, try checking if the numerator is factorable in the second to last step
Uh.. factorable meaning..? When you take out (x^2) from the equation?
like a coefficient
For example
I’ll come back to it for sure as I found the answer , since it was the second to last step that I had, but with (x+7)(x+2) as the denominator
x²-1 -> (x+1)(x-1)
I remember that..
@willow bear like this?. Sorry I got the R and B mixed up
I’ll test it out after I’m done with this practice test, as I think I got it solved correctly here, minus the last step
I don't believe the numerator is factorable, Mr. P.
That’s factoring, when a quadratic can be written as (x-a)(x-b) where a and b are integers
It’s not?
You can remove a coefficient
7,24,35?
an integer, but not as (x+a)(x+b)
@twilit shadow no
Oof
I got my R and B mixed up (I’m using those to represent the dyes)
Uhh... so k = slope, h= amount of turns, and a is..?
In vertex form?
R = 4a + b, B = a + 6b
I don’t think that’s right
I faintly remember this, but I think I’m remembering from wavelengths in calculus... not sure
I’m supposed to convert
@pliant pecan are you talking about vertex form
Standard form...
(h, k) are the (x, y) coordinates of the vertex
For one, they need to be inequalities, and R is the red dye, B is the blue dye, a is the gallons of color a, and b is the gallons of color b
Ax²+Bx+C is standard form.
What henry said
Oh...
A·(x-h)²+k is Vertex Form.
This practice test says that’s standard form. Ouch. Ok, so h and k are the coordinates of the highest point, correct?
Not necessarily the highest point
Well highest or lowest, depending on the graph, this is negative so it’d be the lowest
The extreme point of a quadratic
Whatever. It’s getting really late, I have like 3 tests tomorrow, and I just can’t think correctly. I’ll just ask my teacher to help
With the equation, how would I draw the graph? I could do it by plotting it out 1 by 1 but for a general idea...
h and k are* where the function is centered when x = 0
well the k would be different, my bad.
The x coordinate of the vertex is -b/2a where y = ax² + bx + c @pliant pecan
Yeah, I don’t think what I did was right
To get the y coordinate, you plug in the x coordinate into y(x)
so h = -b/2a, and k = f(h)
Yes
didn't you say you took calculus, do you remember the power rule?
if you do, the reasoning for the -b/2a is pretty simple to explain, relatively speaking
He’d also have to know about maximization/minimization
I took honors calculus in high school but that was what feels like a long time ago.
What class are all these questions for
Now I can’t even understand college algebra correctly. I mean, give me a formula and it’s as simple as plugging it in, but I haven’t done math in a while and forgot most formulas and rules
Pre-Calc does a lot of review.
It’s college pre cal
Well, idk if you could follow this, but worth a shot
anything to spare you from memorizing something that seems random
(Set dy/dx to 0 because you’re looking for an extreme point in y(x))
and the x would be the specific x value that y' would be set to 0 to. We'd then call that specific x value 'h' (for the Vertex equation).
There’s also a formula for the y value of the vertex, but it’s kinda lame
Did you get the process?
nice :)
I understood when @barren hedge broke down getting H, and for K you’re saying I need a derivative. I haven’t done those in a while. I thought I figured out K already by plugging h into the function
That's what you'd do in Calculus, finding the value for K once you have H is nothing special in Calc. Just gotta plug it back into the original equation.
The answer I had gotten shows up as an answer on here so I’m assuming I had done it correctly?
Isn’t the derivative like a slope or something ? Can’t remember it too well
It’s not a key, it’s a choice. It’s a multiple choice practice test lol
you got (h, k)→(-1, 22)?
It’s the slope of the line tangent to the graph at a particular point
Ah
@barren hedge those were the values I had gotten
not that, remember the h is negated when it's inside the argument
Didn’t he negate it
oh
Bruh moment
So then h = -1 would be addition
true
That’s what I did lol
i told you you were right
Oh
totally
Henry b like 
good work
i need a bucket, all this sweat and I'd drown a desert
I feel like this is easy af and I’m over thinking it
To a person who hasn't taken math for a while, this would be challenging.
I meant this problem but to a PhD I’m sure you understand it all lol
Bruh do you think they’d remember some of these formulae
That is the correct triangle area formula right?
yes
Good lol
For the area yea
6ix, I'd plug in h = 3×L, solve for L, and plug it back in to get h
if h is height, L is base...?
Yep.
The question says the height is 3 times the base
I knew it.
6ix b like 
lol
A PhD would probably be too busy creating new theories for Differential Vector Topology or something.
derp
Wdym nvm
I already drew the sunglasses
Start again and substitute this time
You usually only want one unknown in an equation
You already know what b is
Holy fuck I’m dumb as a brick
Did you figure it out
Then I was doing it right, right? When I divided by 4 to get b, and then was going to multiply by 3?
Put the shades back on, I did know it
hm
Is it 1089? It should be, right? Let me prove it, hang on
should be 66 derp
Holy fuck I’m so dumb. I tried to prove it and the area came out as over 190k
I think the problem is that you said the base was 363
Yeah, that can’t be right
why'd you divide 1452 by 4
Because I’m dumb. I plugged in 3b as h and did 3b times b
o
I think this is a bit easier
Isolate L, plug it into the area formula, isolate for h and done
I figured I’d get b and multiply by 3 but that didn’t work out fine
I’m going to hit the sack guys, or at least try to
I gotta cash in my 3 hours of sleep B)
derp, enjoy
Oh yeah, I got it
let the boogie man eat your feet
He She can suck my toes
Night, @plush trench. Thanks for the help
oh, he she will
Gn
Anyone there that can help?

snez
Yeah, so I failed my practice test due to time. Go into spam random answers into my assignment I have rn to get something better than a 0
Do you guys have some sort of tutoring system?
Radius = 10 inches, velocity= 24ft/sec, RPM=?
if you have a question, then people try their best to answer
kinda like a ffa
6ix, didn't you have that exact problem? lol..
I believe I’m doing this right but I keep getting the wrong answer according to my textbook
uh
Wdym? @barren hedge
post the question exactly as stated @lethal oracle
the radians per second
But in this case, RPM probably means Revolutions per Minute.
It’s 45
I take 24ft/sec and then change it to inches per minute
Then I divide by radius
And 2 pi
Maybe I’m making an arithmetic error
Idk
I got 288in/sec
17280in/min
hm agreed
so 275 revolutions per minute was wrong?
Yes
Surely there’s a better way to solve this
The book says the answer is
22=½hb is not 11=hb
It’s not? We did it this way for my last problem though?
For the whole hour I’ve here trying to do this
gotta multiply both sides by 2, 6ix
ye
I got my first exam tomorrow
looks like a quadratic equation to me
Is this literally what I’m expected to solve?
Ya that’s a quadratic
Mine?
yep
So in a quadratic I’d want to get 44 on the other side, right?
I mean factorable
$$\frac{-b±\sqrt{b^{2}-4ac}}{2a}$$
HenryCastle:
yep
Why not just factor it
Yes
how'd you factor that, Alpaka?
44 = h·(h+7) isn't too nice to solve.
I don’t think I can do this without a calculator lol
I got h=-11 h=4
So remember 6ix, you want to find height. A negative value for height wouldn't make sense.
lol
same
oh
I don’t see how I’d solve this without a square root and there’s no answer with one lol
how'd you manage to factor it, Alpaca?
What’s factoring again? Not what is it, but how do you do it? (X-1)(x+1) but what am I putting in for one? A/b/c
oh I see
What is that? Looks like an interesting process
It's basically an educated guess? Like x²-1 = (x-1)(x+1)
So to factor you set up the diamond
diamond? fancy stuff going on
Multiply a and c
Lol
don't mind us if we rob it from you.
It’s okay
Lol
So the coefficient of h in this case
So -44
Yup
That goes in the top
I see that
Now you put b(7)
In the bottom
You see that?
B in this case is 7
You see that @pliant pecan
as in B = 7, not B(x) : x = 7 lol
Ya sorry I made it a bit confusing
i notion that we change the function notation from f(x) to f((x))
Nah lol
-dies-
||wat ;-;?||
Wait
So did you set up the diamond
You got -44 on the top and 7 on the bottom
Right?
The diamond being the X diagram
Just took my first test btw. Spammed my practice test and started answering what Ik on the actual test. Went pretty bad. Had to sub by 00:00 though. It’ll get replaced by my final exam grade though
@lethal oracle yes, I’m there
Now you need to find two numbers that multiply to be -44 but add to be 7
What two numbers do you get?
But they don’t equal zero 
Not yet
Wait, so why’s h coming in?
Yes
h is a specific value of X that we're trying to find,
It’s coming in cause we are basically breaking up the orijgnal quadratic into two binomials that are equal to the quadratic that we originally had
Yes
And 4 would be the answer
Those are your answers
Got it
No both are
(btw these are different h's, not a systems of equations. So something like h₁+ 11 = 0, and h₂ - 4 = 0)
Well it’s impossible for -11 in this case so I’d have to take 4, logically
Well it depends if it’s like a question asking about time
Then yes
Negative time is impossible

oh but this one is finding height ("length")
This will work wonders in the future 
(the only problem with this technique is that you won't always be able to find factors, in which case you'd have to restart and use the quadratic equation to get the answer)
Lol, it’s nothing but anime emojis in this server
ye
you bullying our emojis?? 
Lol, of course not 
and easy to check once you get comfortable
Yeah, I’d rather try to factor then use the quad than just go straight to quad
we all do
Is there a good practice book for algebra you know of, @barren hedge ?
but physics courses will teach you that it's not aboutbwhat you'd rather d-
Lol
I don't know any books lol
You said you had one 
like Classical Mechanics an-
no I was commenting when you were saying it is "easy" but you found it hard
“To a mathematician with a PhD, this is easy”
and saying that to a Math PhD they'd find algebra ez
but to someone who took a break, they'd find it a challenge
oh lol
I'd like a Math and Physics PhD
but I am in college though (like most of us)
no im actually in elementary school, fully qualified to tutor calc 3 and differential equations
ok internet is hard to say things in a joking way, I almost believed myself
Im a high school junior
What math are you in?
I wasn’t always this dumb btw. I took honors calculus in high school. I was able to skip algebra and geometry through an exam in high school (geometry one bit me back later as I’d need to apply it in calculus and didn’t actually take the class), and yeah..
Precalc
really weird. Honors Calc was a thing but I think they stopped it and went for only AP Calc
What hurt me(fucked me up) was that I left and joined the military, where you don’t use this level of math 
And so it left me
yeah.. the muscle you don't exercize, atrophies. In your case, math.
At least you got a life (whereas I'm still living with my parents >.>)
Lol, if you call that getting a life
Do you guys play video games
Used to, but I play a online kid's game (to DEV games, I'm not a creep, sheesh)
Lol
Ah lol
Why?
Idk I always like finding new people to play with
USUM was great, I hate that people frowned upon it
They finally had an event to get them shiny??
Nice, did you legitimately get yours ?
At GameStop and you need a freaking app or something to get the codes
Still have to pick up shiny zygarde from the mailman lol
I’ve played literally every single game (to the main series- so not including every mystery dungeon)
The zygarde codes still work?
No
I just haven’t picked it up in game yet
Not competitive at all. Haven’t got the slightest clue. I just play for fun and gather Pokémon for the looks lol.
Shiny Ho-oh was nice to finally get after all the SRs
Which is why you’re a flaaffy / ampharos fan .. lol I’m kidding. I used it in gen 2 as well.
Yeah, I loved the fact that we could get all the legendary Pokémon with usum
Tbh, I wish they’d go back to the way they did it in gen 4 where you got a little extra bit of story line for when mythical Pokémon were released. Unlike how they just give them to you now.
You want e to the x^2?
yessssss
$e^{x^2}$
⚡Amphy⚡:
RokettoJanpu:
$\frac{a}{b}$
\frac{numerator}{denominator}
thank you both
so
So how do i solve the following inequality: $e^{x^2}-e^{x+2} > \ln(\frac{x+3}{x^2+1})$
tomatoes:
Looking good now
👋
he did 
big oof
i don't think this has a nice solution at all
jan Niku:
then uhh
well wolfram can do it and it seems like a simple solution
cool cool
you dont need to do it
im not sure that method even works
i just dont like exponents in exponents
so e^x(e^x-e^2) feels better
😦
e^(x^2) is not (e^x)^2
no
it is not
e^x * e^x is e^(2x)
you really really should review your exponent laws
i dont have time im trying to keep up in class
so um does anyone have any ideas
Here is the inequality once more
$e^{x^2}-e^{x+2} > \ln(\frac{x+3}{x^2+1})$
tomatoes:
,w exp(x^2) - exp(x+2) > log((x+3)/(x^2+1))

wow ok this must be much more difficult than i first thought
which doesn't necessarily mean that it is not simple
although it should be somewhat simple
like high school level
Does anyone have any more ideas? Absolutely anything else
@viscid thistle I think I got it. The left side stuff is completely irrelevant maybe; take the right side only for now;
rewrite the log of a fraction out as a difference -> log(a) - log(b)
Your only real solutions are when the inside of the log are greater than zero; solve for those inequalities
@viscid thistle yes i have
@cyan zodiac ok i'll do that
well that leaves us with x>-2
Tomatoes
Can you break this into an inequality of functions?
I mean it already is
But more obvious ones
Noticing that $e^t + \ln(t+1) $ is an increasing function is a possible path
Mat:
^
Actually
oh that was actually asked previously in the exercise
F(x)=e^2+ln(x+1)+1
it asked us to prove that it is an increasing function
then to solve the inequality
e^x^2+ln(x^2+1)>1
Move everything to >0
And use that
oh wait yeah
Mm was it e^2 or e^x ?
$e^{x^2}$
tomatoes:
In F(x) I mean
oh um e^2
Umm, in that case you would need to prove the function for the inequality is increasing I suppose
But the approach is the same
Dunno if this is proper enough, but here's what I tried: https://i.imgur.com/VqIC9nX.jpg
US letter full height, cropped width
what exactly is giving you trouble here
I really just can't comprehend the steps needed to be taken. I've looked at videos of similar problems, and they've given me insight. But even so, I'm not quite clear on how to go about the problem.
The furthest I've gotten is rationalizing the fraction. (and that was only because I realized they did so in one of the videos)
That's the right answer. @blazing monolith
That's why I was confused. I didn't know how to solve it myself.
JY1853:
Feel like giving full solutions isn't great
It helps me a lot. One thing I need to ask.
@blazing monolith
Why is the rationalization a positive root(x), when the original numerator is minus?
a^2+b^2
a^2-ab+ab+b^2
(I really need to learn how produce the fancy text
Check your work on this expansion
I see the issue I made already. The way JY formats it makes it much less confusing. He has the numbers separated via parenthesis, whereas I factored it automatically. (plus I factored it wrong, my rationalization used a minus square root)
And that's why you do your work step by step
TY guys.
I'm doing an investigation on Bezier curves with a maximum of 4 control points. Does anyone have a suggestion for a problem/topic that I can model using geogebra?
oops wrong channel
Hey if for (x-2)(x+2), the roots are x=2 and x=-2, what are the roots if there was a negative sign in front: -(x-2)(x+2)
when will the value of the expression be 0?
oh shit i'm dumb lol i see roots would still be the same
right, since the - never creates or changes a 0
in fact, if you prefer, you can actually distribute the - in to one of the factors:
$-(x-2)(x+2) = (-x+2)(x+2) = 0 \ \ -x + 2 = 0 \implies x = 2 \ x + 2 = 0 \implies x = -2$
Namington:
this isnt necessarily to solve it or anything, but it can give one "interpretation" for why it doesnt affect the answer
At my school, I taught myself all of Algebra 2 and all of Pre-cal so I didn't get all of the tips and tricks, loopholes, etc. I never could figure out a way to memorize/remember the unit circle without a note sheet. Can someone hook me up with a good method?
what do you mean by remember the unit circle?
yeah like pi/3 pi/6 pi /4
Well, you can do that by remembering a couple of special triangles
the isosceles right triangle and the equilateral triangle
how would this translate to setting up the coordinates on my unit circle. for example the coords of pi / 3 are (1/2, sqrt of 3/2). Its been a little bit since ive worked with the unit circle so yeah. Sorry if i have the big dumb rn.
well, your coordinates are $(\cos \theta, \sin \theta)$
Element118:
so, all that needs is calculating/remembering sin and cos for special angles
Can someone explain the reasoning behind why the first 3 are even, my brain just isn’t working
you know the definition of "even function", yes?
yeah
and you know how multiplication by -1 affects how a function "looks"?
yes
it's a vertical reflection, yes
does being vertically reflected change whether it's symmetrical about the y-axis?
no
hence, (a) is even.
similar logic applies to (b) and (c); the transformation applied doesn't affect whether a function is even
Yeah I see now
we can also do this more algebraically:
Idk why I couldn’t see that
the definition of an even function is f(x) = f(-x)
so if g(x) = -f(x)
g(x) = -f(x) = -f(-x) = g(-x)
i.e. g(x) = g(-x), so g is even
again, a similar thing can be done in parts b and c
if g(x) = f(-x), we have:
g(x) = f(-x) = f(--x) = f(x) = g(-x)
so g(x) = g(-x), again showing g is even
and if g(x) = f(x) - 2:
g(x) = f(x) - 2 = f(-x) - 2 = g(-x)
so, again, g(x) = g(-x)
this algebraic approach should also show why it fails for (d)
actually, for b, you can just say g = f lmao
Yeah okay
since like
Thank you
yeah, true
f is even so f(-x) = f(x) by defn
thats much more direct
Hi
simplifying question. In the last part X= 3/(sqrt 5)
Why can't you leave it as it is. Why multiply sqrt 5/ sqrt 5 to make it X=3 sqrt 5/ 5?
because we really like integers in our denominators
you CAN leave it as is
it's just that some people insist on rationalizing denominators
at all times
EvilRobotOverlord:
Does a function being 1 to 1 mean that it is strictly increasing?
no
not even that
oh
take f: [0,2] -> R given by f(x) = x for x in [0,1) and 10-x for x in [1,2]
one to one? yes
monotone? no
wait do you mean these lines
cause i think thosr are monotone
ohh
it's like
one function composed of those two
but like there are 2 values of x that give the same value for y
does that count as 1 to 1
?
i gave you a PIECEWISE function.
You need to choose which function to use depending on which piece of the domain you are in
I have no idea if this is the right place to ask, but...
https://i.imgur.com/DbL38ME.png
Is it possible to make an equation for this?
I want to be able to get the value of y when x is anywhere between 0 and 1
looks like statistics
where you want to fit some sort of best fit line
how do your points look like?
what model are you fitting?
@neat terrace
yeah, just get the equation of that best fit line, and then substitute in the values for x
that's one way about it
I need an exact result though
yeah, you can substitute in the value for x and get an exact result
or are you going to linearly interpolate between two points?
that's another way to get values
fourier series
You can approximate by sin functions or polinomials
But the simplest way is just to make it a piecewise function
haha we only have it at a couple of points though
$f\left(x\right)=\left{0\le x\le.15:\frac{72}{0.15}x,.15\le x\le.19:\frac{6}{0.04}\left(x-.15\right)+72,0.19\le x\le0.23:\frac{6}{0.04}\left(x-0.19\right)+78,0.23\le x\le0.26:\frac{6}{0.03}\left(x-0.23\right)+84,0.26\le x\le0.84:\frac{90}{0.55-0.26}\left(x-0.26\right)+90,0.84\le x\le.87:\frac{6}{0.03}\left(x-.84\right)+270,.87\le x\le.91:\frac{6}{0.04}\left(x-.87\right)+276,.91\le x\le.95:\frac{6}{0.04}\left(x-.91\right)+282,0.95\le x\le1:\frac{72}{0.05}\left(x-.95\right)+288\right}$
desmos format
DarK:
can anyone explain why theres a difference in counting combinations in these 2 situations:
when deciding the probability of throwing a dice roll with a SUM IS 9 OR HIGHER: 6-3 and 3-6 are counted as two different combinations
when deciding the probability of WALK AT LEAST ONCE in terms of transportation with two trips: WALK - WALK are not counted as two combinations
It doesn't make sense to me why it'd be counted in one situation or not the other. For the total sum, it doesn't matter if the first or the second throw is a specific number. Neither should it matter when we try to determine if a person has walked at least once
WALK-WALK is the same as WALK-WALK
Is DICE A: 3 and DICE B: 6 not the same as DICE A: 6 and DICE B: 3 with that logic?
Because the outcome is the same
I don't understand the logic behind why 6+3 = 9 is not the same as 3+6=9
And if those are counted as two different combinations, then WALK morning and WALK evening is not the same as WALK evening and WALK morning
...
2 times
How so?
There's only one possibility:
The first roll is a 6
And the second roll is a 6
hm
But if we want to count the probability of rolling a 6 and a 3, in no particular order
There's two possibilities:
First roll 6, second 3
Or first roll 3, second 6
do you know what $f \circ g$ is?
Ann:
No, I don't... That's what made it even more confusing
Function Composition
Oh, is that what it means?
Right...
i mean idk
Any idea on how I would go about doing this?
For all those people who find it more convenient to bother you with their question rather than search it for themselves.
Function composition is basically where you plug in a function to another function
f o g = f(g(x)) if that form seems more familiar to you, it’s just a different way of writing the same thing
How can i do that problem @willow bear
compute the angle between your vector and i
how do i factor when a is not 1
,w tan^-1{3/1}
like for 2x^3-5x-3
,w 1.249rad.to degrees
Quick questioon y'all
So like, I understand what they mean by (f^-1og^-1)(x)
But what happens when they say
(f^-1og^-1)(2)
Instead of the x at the end
They replaced it with the number 2.
What do I do with that?
What's the difference between f(x) and f(2)?
Yes
Bruh

@viscid thistle hey friend 🤡
@river coral hi friend
3^15 = 3^10 * 3^5, and 27 = 3^3
2^10 * 3^10 = 6^10
6^10 / 6^12 = 6^-2, and 3^5 / 3^3 = 3^2
then simplify from there
alternatively, break down 6^12 into (2*3)^12
which becomes 2^12 * 3^12
and then you can, again, simplify from there
im confused about where the 3^25/81^12 came from
i think thats there as a "here's some common mistakes which you shouldnt do"
since theres no justification for that
so is the only part that really matters
i'm just really confused because it seems like my professor's work is so messy
for 6^12 use the formula: (a * b)^n = a^n * b^n
yeah, the circled is the only part that matters, the rest is random and unnecessary (probably to show another case).
anyone know how to solve this problem?
your answer for volume doesn't seem simplified
seems correct after simplification, though
you should get a simple trinomial
$(8x^3 + 16x^2 + 6x) - (6x^2 + 24x) \ \ 8x^3 + 16x^2 + 6x - 6x^2 - 24x$
Namington:
hmm
A square hut with side lengths of 5 m is to be surrounded by a veranda of width x metres.
Find the width of the veranda if its area is to be 24 m2.
can anyone help me on this one?
what have you tried and where are you stuck
$\sqrt[n]{a}\cdot\sqrt[n]{b} = \sqrt[n]{ab}$
Jiramide:
Multiply the both sides of the fraction by the denominator's conjugate
a^1/3-b^1/3 wouldn't work right
Ah it's cube root mb
oh conjugate is only for square roots?
Yeah since only difference of squares factor into term * conjugate form
Have you learned about the sum or difference of cubes?
Hmm I'm not really sure how you'd do this (you could probably arrive at sum of cubes if you really stare at the notes) but I'm on phone and it's rlly hard to type
I need help with sequences

Iirc you just have to find how much the sequence changes each term to get from 22 to 64 in 6 terms, and if you know how to write a recursive and explicit formula you should be good
Mechanist FD:
@upper flint First term is (2*1-1), second (2*2-1) and so on
@proud sparrow Ik
so you start at 1 and end at n
$\sum_{k=1}^{n} (2k-1)$
ramonov:
o sorry
^
n
the answer is quite nice
yeah, this is a fairly well-known sum, it turns out.
in fact, you might be able to guess the pattern just by testing
1 + 3
1 + 3 + 5
1 + 3 + 5 + 7
Hello, someone can help me?

why did you write
x^2 for k=0
those caluculations would be for the first term
what is the question asking you to do?
o_o just replace k by 0 Everytime I saw a K
Oh I see
I did a mistake
What about that? Is that correct?
Σ means "sum"
=2
and then you'd have to write out the next few terms
k = 0 below, and n above, means to sum the terms from 0 to n
So you've got the first term, but there's more
followed by ... and the final one or two terms
I did this for the third one 
Really? Why?
these sums and sequences are better left as fractions so see their patterns
Oooh okay
You generally don't want to use decimals in a math class. They imply you're approximating the answer
how many terms did you write for the second one?
5
that sum doesn't end at i=6
you'd need indicate that it keeps going until i=n
i meant for your SUM of (2i -1)
followed by the term where it ends
the last 2 terms is usually better but one is enough
But it says n, there isn't an actual end
yeh
Cool
for the first one, you could leave them in the form ^4
and for the current question, leave them as powers of 2
I don't want to risk it, this teacher I have it's kinda scary to me
Is this okay :/
the denominator is
2k + 1
not 2^k + 1
Right...
I didn't changed much though, still send prove that I listen to you :)
Thank you very much
don't write -1x or 1x^2
just -x and x^2
remember the ... and nth term and you should be good
Thanks again Ramonov, have a great night
Not sure what I replace here.
what've you tried so far?
G-father, you’re missing the -f(x) part
(((x^2 +1) + h) - (x^2 +1))/ h
result is 1
Yes
X-x. Cxl each other out leaving you with h/h which is 1
thank you!
When do you know to use "{}" or "()" for answers
Ex) Why does this one use "{}" for it's answers which are {-4,-4/3}
when this one uses "()" for it's answers which are (7,11)
Sorry if I cut anyone.
curly brackets {} denote a set
round/square brackets (), [], (], or [) denote an interval
the first question uses {} because there's a finite set of solutions
I’m about to start an astrophysics corse it’s I’ll@probably be taking calc and physics
which can be listed individually
the second one uses () because you can't list the solutions
its an inequality, so the solutions will be an interval
{-4,-4/3} indicates that the solutions are -4 and -4/3, and ONLY those
(7,11) indicates that the solutions are all numbers BETWEEN 7 and 11
(excluding 7 and 11 themselves)
for more, look up "set notation" and "interval notation"



