#precalculus
1 messages · Page 252 of 1
since the stationary point is positive/negative sqrt 2/3
x-coords of the stationary points
,w evaluate -4sqrt(6))/9 + 3
where did the negative come from?
the question is how youre getting a positive
Heres my working, its really confusing but i basically found the stationary points and then tried to sub it ?
oh shoot
bottom box
there seems to be no convo going on here at the moment
Oh ok
What am I looking for 😔 I’m lost
@echo wagon can u help me
Is it (3,0)?
Can anyone help
there is an interval where the graph decreases
between 3 and 5 on the x axis the graph has a negative slope and the y value decreases as you move forward
is that what you had in mind?
What does decreasing mean @grim sand?
Going down
it should be the interval (3, 5)
as that's when the gradient is <0, and make sure the brackets are round since the points aren't included
for you
It's for you, lol
Oh
if you look at the cubic graph, when x is < 3 the graph is going up yea?
@echo wagon plz translate 🥺
Since you say it has to go down, where is it going down?
same with when x > 5, the only time the gradient/slope is negative is between 3 & 5
At 3 on y axis ? What does that mean?
same with when x > 5, the only time the gradient/slope is negative is between 3 & 5
@amy.ames.aims#0827 I’m sorry but I don’t understand..
Yeah exactly
Now if you had to describe the x coordinates of that part of the graph, how would you do it?
0
0?
Cuz the line start at 3,0
There's literally no point on the entire graph where the x coordinate is
0
At least the visible part
a line starting at 3.0 has x coord 0?
I’m confused
(3, 0) which is the x coordinate?
The 0
No
Yeah
And the Y is 0
You really shouldn't get that wrong anymore
And at what point does it stop going down?
And what is the x coordinate of that point?
So do you agree it is going down for 3 < x < 5?
Yes
That's a fair point. But when we consider when a function has a specific property, we look at which part of the domain it has that property
And the domain is the x values
So how would you write the interval of the x values with 3 <x < 5?
(3,5)
So that's the answer
That's the part of the domain where the function is decreasing
So when we looking for when the function is decreasing
We only look for domain values?
What if it’s increasing
Well, everywhere else
You always look at the domain
If you ask WHERE DOES A FUNCTION HAVE SOME PROPERTY then you answer with a subset of the domain
One reason for this is that a function can have multiple points with the same y value, so if you refer to the y values, it isn't clear which point you are talking about
Whereas every point has a different x value
You don't know about derivatives yet? If not, yeah, graph it
What are derivatives
Lol, so yes, graph it
I graphed it and looked at Domain only and got (-2,4)
Show me the graph then
Yeah, looks right
How do I find limit
My teacher was supposed to teach me this but he doesn’t explain he just does the math
Im dum
@235711131719232931...#8067 it’s ok I’m dumb too
My teacher was supposed to teach me this but he doesn’t explain he just does the math
@grim sand oof that's rough
Yes so I’m lost
My teacher was supposed to teach me this but he doesn’t explain he just does the math
@grim sand That's not good, at all
do you have a text book you can read through or anything?
No it’s online so it’s even worse
i can give you my notes if you'd like, i think we're doing the same course
i have no idea im australian ://
it's yr 11 maths, but your questions look similar to what i did last term
I’m year 12 math
yep p much,,, i'm little slower since im yr 10 tho ://
get a precalc book, I'm doing Larson's. Good IMO
I’m year 12 math
@grim sand the questions look the exact same O-O
Yes
I was supposed to take this in year 11
But
My counselor said no
So I had no math for 2 years
So.. how do I find limits
here's the first part,,, i'll put together the answer sheet
Oh cool it tells me limits
i wish i could help
do you want the explanation or just the answer?
don't worry Jupiter
i like learning not a straight answer
ok sure;
after two years of not doing math it will take a few painful weeks but then you'll feel much better
just don't give up and be consistent with your daily practice
ok so with limits there are 3 different types of 'cases'
- where x is a constant number, (for example f(x) = 2)
- where the function has x terms but has a numerical denominator (eg 2x+3 --> the denominator is 1 in this case)
- where the function has x terms but has 0 for a denominator
can you tell what 'case' yours is @grim sand ?


how do you expand
you take out 'like/similar terms' and group them together
i'm sorry its nearly midnight here,,,, i don't want my mum to whoop my ass
just ask away tho, i have plenty of time
yes!
so now its just 3^2
uh, not quite
it'd be x(3x - 1)
because 3x^2 is equal to x * x * 3
and -x is equal to -1 * x
it means to take out any common factors between your terms
@echo wagon plz dumb it down for me
guess luna is afk
so whats the answer to the equation? @delicate rivet
skdjhk i'm sorry i keep disappearing,,
factorise and sub it the small number at the bottom
wait is it an infinity sign?
ok bad wording, the little symbols underneath 'lim'
hmmm,,, i don't think i'm the best at explaining this for you,,,
@delicate rivet i recommend staying in alpha so your attention isn’t divided while you’re getting help
that means that x is approaching something
@delicate rivet i recommend staying in alpha so your attention isn’t divided
@stuck lark yea,,, that's really on me i took up too much
i point it out mostly bc it’s rude to the helper when you’re not totally focused
not much computation needed, just note the polynomial degree & lead coefficient, then recall corresponding end behavior
google: polynomial degree, lead coefficient, end behavior (of polynomial functions)
and it’s really for jupiter to look this up (leave it jed)
study it
once you read and try your best to study, then you can come back and ask questions
i point it out mostly bc it’s rude to the helper when you’re not totally focused
@stuck lark You're right, and I apologise. I bit off more than I could chew for a short period of time
thanks @delicate rivet
but the apology should go to anubis
and jupiter if you feel like you can attempt the question after studying then here, to start you off
not much computation needed, just note the polynomial degree & lead coefficient, then recall its corresponding end behavior
computation is referring to your working,
Can someone tell me what this type of equations are called so I can watch YouTube videos
The limits and stuff
like the app?
Tried it freshman year it didn’t work out well
i'd suggest your teacher then, or a tutor since they can help you with specific questions you have
@grim sand take one word in what @stuck lark wrote at the time and try to unwrap it and see what it means. You kind of have to go through this because mathematicians use these to somehow make sense of it all. (Imagine some numbers being written in arabic, some in Kanji and some in roman numbers, we need common language for them)
Oh
So it’s like different math languages but we need a specific one from each to combine to get to know the one I’m looking at?
well no but your example is even better. Yeah, each formula or even sentences like the one the guy wrote to you, they represent a bag of math that will solve your problem
but you first have to go through the trouble of understanding them
Okay bet
My teacher can’t teach so he’s useless
@grim sand surely theres more than one math's teacher in your school? what about the math's co-ordinator?
Got any videos that are spot on or do I have to look for myself
idk, i'm sorry mate
@grim sand surely theres more than one math's teacher in your school? what about the math's co-ordinator?
@amy.ames.aims#0827 idk what that is but we only got 1 pre calc teacher here
And it’s online so it’s harder
ooo, what about the other people in your class?
you could always shoot him an email asking for 15 minutes of one on one?
that's what worked for me when I fell behind a bit
Talking to him is a no man I don’t understand anything he says
And 90% of my friends r as clueless as me
what about the people doing well? would they be willing to help?
I think I used to be in similar condition when it comes down to education as you @grim sand where are you from?
that's in america right?
Yes
ohh k tyy
what about the people doing well? would they be willing to help?
@amy.ames.aims#0827 no clue I’m too scared to ask them cuz idk them
hmmm first place i'd start is factorisation videos then?
come on man that's at least 500% better and faster to get something if you can talk to someone who knows it and can talk to you in person
you need to have a strong grasp of algebra before you can tackle any of the graphing stuff
I don’t know how to get in contact with them
^^ what allione said
We use zoom and zoom doesn’t let me email them
U can dm from zoom?
go to them when you see them goddamnit they'll might even thank you for asking for help
go to them when you see them goddamnit they'll might even thank you for asking for help
@sour wagon 😔🤚🏻
U can dm from zoom?
@grim sand yes? i think so
Idk it’s my first year using zoom
click alt h / open chat and toggle down for the person you want
idk either man i only use it for co-curriculars,,, we use microsoft teams
My pre calc period ended 2 hours ago I’ll do it tmr hehe
2hrs? skjhkj aight u got the rest of the day to start learning the basics to differenciation calc
Glll
like on your own or in class?
On my own
oo thats a good start,, just keep at it
use another letter for the input of f and z
and then in the table put f(g) and z(g) for your columns
are you sure it isn't pi/2 early? 😃
Im just having a brain fart bc this is old material to me but how would you find the y=ab^x form of the exponential function f(x)=5^x8^x ( I know the answer a=1 and b=40 I dont understand how to work it backwards)
$l^k\cdot m^k=(l\cdot m)^k$
The Godfather:
@jade iris
@blissful ridge why is a=1?
Use the identity, I gave you and tell me what you get?
40^k
$40^k=1\cdot 40^k$
The Godfather:
is it because 1 is considered an initial value so there isnt but the intial value cannot be zero which would the expression not valid?
@blissful ridge
You can multiply 1 so any given expression and it won't change the value
ah ok so what would be an example of a would not be 1 @blissful ridge
The Godfather:
so now a=2 and b=39
Yeah
Yep get it now @blissful ridge thank you!
Parentheses?
i think it looks correct
A cubic function generally has the form
f(x) = ax^3 + bx^2 + cx + d.
If we know that for some x-value x = p we have
f(p) = 0,
then it must be true that x − p is a factor of f(x). Since we are told that
f(3) = 0,
we know that 3 is a factor
@viscid thistle Can you help verify the last statement of "3 is a factor"?
Why was I tagged with this question
you might be able to help me since you have, "advanced" as a tag
Can you... not tag people without a good reason
... alright man
yeah
I'm not very good at this either but I think that means
(x-3) is a factor of the function
like, if you divide the equation by (x-3) the remainder would be 0
cuz of the factor theorem
Yes, this looks like a restatement of factor theorem
But for a particular value of 3
thanks
And yes x-3 is a factor sounds better to me
Dozenford:
Dozenford:
well i guess that does also work
which is easier though
they are equivalant anyway
I figure sin^2
actually u need to divide the 1 by 2 as well
Yes my bad
do u know the expansion of cos(2x)
2cos(x)?
no.....
no that isnt the expansion
Can you explain it to me please
it is cos^2 -sin^x
Oh
do u know expansions of sin(x+y) and cos(x+y)
$2sin((x+y)/2))cos((x+y)/2)$
Dozenford:
To be honest, off the top of my head I do not
I can off of a formula sheet but that isn't exactly knowing it
This is the file I was going off of
Is there a better resource?
if you don't want to open the file which I understand i'll send a screenshot of it
it is here
ohh I see
I see my error with the org problem
I was supposed to use the Pythagorean identity
Okay so for instance: $If sin^2+cos^2 = 1 then cos^2 = sin^2 - 1$
Dozenford:
do you know this picture
Yeah the unit circle
I have a question, is this function exist?
@ember crane well cot = 1/tan so yes
but the square part is also applicable right?
yeah
@ember crane
from cot(x)=1/(tan(x)) you can square both sides to get to that conclusion
@ember crane
$cot(x) = \frac{1}{tan(x)}$ then we have, $cot^{2}{x} = (\frac{1}{tan(x)})^{2}$ then we get $cot^{2}{x} = \frac{1}{tan(x)}\frac{1}{tan(x)}$ then finally, $cot^{2}{x} = \frac{1}{tan^{2}{x}}$
Sasuke Uchiha:
...
wow.... thnks
why does 1 question need to be answered 3 times.
Yeah like
I have no idea
why does 1 question need to be answered 3 times.
2 times
nah, its 3 XD
1 from CEO of your data, 1 from Al3dium aand one from Sasuke Uchiha
yes sir, thnk u very much 😄
Ceo of your data didn't answer the "but the square part is also applicable" lol
So it's 2
but i explained with the most detail 😎 me acting liking that matters
...
lol XD
$4\log x-3\log(x^2+1)+4log(x-1)$
am I right to start off by doing:
2+4i = 2+ai / 4+bi ?
Albot1288:
any one know how to rewrite this into a single logarithm?
power law and then sum/difference to product/quotient
huh?
those reference the log laws you would need to apply
so I don't just simplify it?
simplificty is subjective here
I think I should rewatch the lecture tbh
$a\log(b) = \log(b^a)$ would be the power law
ramonov:
which you should apply to all your terms if you intend to combine them into a single log
as the other law(s) you would need to apply are: \
$\log(a) + \log(b) =\log(ab) \
\log(a) - \log(b) =\log\br{\frac ab}$ \
(for $a,b > 0$)
ramonov:
so for mine it would be $x^4+x^6+1^3+x^4-1^4$ then simplify it. Log is not part of the final answer he says.
Albot1288:
ramonov:
and applying the power law doesn't make the log dissapear
I think he means after it's simplified into a simple logarithm don't put the log into the answer bar
like if it's $logaB+C$ just put $aB+C$
Albot1288:
um put proper parentheses please
regardless you're applying the proper steps in combining the logs
ok
refer to the power law above and tell me what you have after applying it
don't bother expanding them btw. leave it in exponent form.
I'm sitting here trying to memorize the unit circle lol my brain is saying no
Don’t try to memorize it
try to memorize the methods that created it
So you can logic your way through piecing it together yourself
will do
I did it like this but how do I put that into typed form?
Nvm got it
$(x^4(x-1)^4)/((x^2+1)^3)$
Albot1288:
Looks alright to me
And simplification is subjective

how would you simplify it? -ty btw
\verb|(5x^3/2)/2| reads as $\frac{\br{\frac{5x^3}{2}}}{2}$
ramonov:
but if you intended $\frac{5x^{\frac32}}{2}$ represented by \verb|5x^(3/2)/2| in plain text, that would be simple enough
ramonov:
hmm yea i understand, but are there any that match one of the answers?
i think i'm simplifying it wrong or something,,,, i can't get their answer
x^1 * sqrt(x) = x^1 * x^1/2 = x^3/2
sorry but what's a radical?
oh nvm i had to look it up
x^(3/2) = (root x)^3 yea?
x^1 * sqrt(x) = x^1 * x^1/2 = x^3/2
@novel cargo ohhhhh thank you!

true
how do we know when the gradient of a graph is defined?
when the function being graphed is differentiable
i.e. when the limit $\lim_{h \to 0} \frac{f(x+h)-f(x)}{h}$ exists for whatever values of $x$ we care about
Ann:
what is the gradient of the graph?
i think it's slope in america?
ahh, thanks
i.e. when the limit $\lim_{h \to 0} \frac{f(x+h)-f(x)}{h}$ exists for whatever values of $x$ we care about
@willow bear ohhhh thank you
amy.ames.aims:
well there are cases when the limit exists but the slope does not
or is not differentiable
wait how come x^1/3 isn't differentiable?
it's not differentiable at 0 because the limit up there with f(x) = x^(1/3) and x = 0 works out to +∞
you have a vertical tangent line at 0
gotcha,,, tytyyyyyy
like abs(x) at zero is not differentiable but has a limit
no, $\lim_{h \to 0} \frac{|0+h| - |0|}{h}$ does not exist.
Ann:
abs(x)?
|x|
ohh
az, what you might have been trying to say is that the absolute value function is continuous but not differentiable at 0
yeah,
which is true, but (a) tangential to what i was saying and (b) poorly phrased on your end
does anyone have an example problem of "find the tangen of [x] curve at point [z]?
i need to practice and I've already done all the example problems in my book O-O
oh sure i can make you some if you want
yes please!
how many do you want
like this?
uh what every suits you, but maybe at least 3?
ok
wait do you have any problems about finding the equation of the tangent (i don't think finding the gradient of the graph will be on the exam)?
In each exercise, find the equation of the tangent line to the graph of y = f(x) at x = c.
[1] f(x) = 100x/(x^2 + 1); c = 2
[2] f(x) = cos(x) - 11x; c = 2π
[3] f(x) = e^(5x) + cos(2πx); c = 3
[4] f(x) = sqrt(x)/(x+7); c = 9
[5] f(x) = sin(2πx^2); c = 3/2
ty!
is 1) y=8(4x-3) & 4) (-3x+75)/1696?
(1) doesn't match my answer key
oh shoot, let me try again
and neither does (4)
hmm i'll go read over my textbook and try again then
ty for this
is 1) y = 8(2x+1)?
no
Could you check over my working please?
oH, ty let me try that again ;-;
um,,, how would you find the derivative of 1) quickly?
quotient rule
I think my teacher skipped over that? we only learnt the chain rule
could you go over it with me please?
wait you didn't learn the quotient rule??
ok then you'll have to use product & chain
very first line, you mis-parenthesized 100(x^2+1)
dont mind the bad handwriting,
lol
that's bad handwriting?
i've seen way worse
anyway
lemme check this
,w d/dx 100x/(x^2+1)
aight yeah you're good
oh yea, sorry about my brackets they're just there so i can write in the multiplication symbol so i remember better
$100 \times x^2 + 1$ reads as $100x^2 + 1$ and not $100(x^2+1)$
Ann:
order of operations
no
y - 40 = -12(x-2)
do you not then bring the -40 to the other side creating
y = -12(x-2) -40 ?
no such thing as "bringing" anything to the other side
also, you wouldn't go from z - 6 = 11 to z = 11 - 6 would you?
ok bad wording, do you not add 40 to both sides?
oH skdjhdkj stupid mistake
it then you would expand and factorise for the answer correct?
you don't really need to factor the 4 out tbh
really? doesn't the answer need to be in the simplest form?
the answer is -12x + 64
or
-4(3x-16) right?
ohhh right right
thank you so much for your help,
||i can't believe it took that long for me to do one question 😭 - the amount of careless mistakes i made-||
yeah the careless algebra mistakes will cost you a lot of time
ikkk it's one of my worst habits,,,,, idk how to fix it tho,,, i just hope i get enough sleep the day before the exam
do algebra but slowly
how to fix algebra mistakes 101 : do more problems related to simple algebra and a lot of them
you... just do? $\frac{\sin(x)}{x \cos(x)}$ can be broken down into $\frac{\sin(x)}{x} \cdot \frac{1}{\cos(x)}$ just fine
Ann:
ohhh okok thanks
lol what was confusing about that 
what is f(x)
i dont know what you are on about
verified this, which was relatively difficult for me
I don’t know either anymore
oh, sorry, didn't realize conv was going on
So it is the same thing
what is the same thing?
yes
They are both functions
well it depends on what f(x)
So when I solve for F(x) I can also solve for G(x) the same exact way
if f(x) isnt g(x) then they arent the same thing
if and only if f(x)=g(x)
He wasn't sure whether calling a function f or g was the same thing

The name of a function is arbitrary
@grim sand g is just a name
sometimes when you have two or three functions they are called f, g and h
but it's not a hard rule
it's like calling a variable y instead of x
So when I try to sketch piece wise functions it’s usually F(x) but this equation is G(x), I’m asking if I can sketch it the same way as I sketch F(x) or is there something different
the name of the function has no bearing on its graph
the name is arbitrary
the equation that defines the function makes it clear how to plot the graph
also the domain
are the equations that define G(x) and F(x) the same?
f=G
also the domains?
Yes
then they are the same
the could be Z(x) or Barbie(x)
If f(x)=G(x) for any point x then f=G
make a right triangle#
seriously make a right triangle
make two of its sides 3 and 8 in a way that gets you an angle with sine 3/8
oh, rewrite the inner piece as an algebraic expression?
He can just use $\cot(\arcsin(y))=\frac{\sqrt{1-y²}}{y}$ too
Oh I was going for an algebraic way
Al𝟛dium:
That works too
👍
bruh ok everyone kind of just went and ignored me
Your method leads to what Al suggested
Yeah
Yo we have this activity and thw teacher didnt even teach it
How can J find the equation of the ellipes with the center of origin (0,0) the foci have coordinates (4,0) and (-4,0) and a vertex is at (-5,0)
In the general equation of ellipse
$\pm ae=foci$ and vertex is $\pm a$
The Godfather:
And we have a relation
$b^2=a^2(1-e^2)$
The Godfather:
Oh its conic section of an ellipse
$ln (1+x^2) + \frac12\ln x - \ln (\sin x)$ would this rewritten be
$((1+x^2)x^1_2/sin(x))$
Albot1288:
he says to not put it in only the numbers after it.
question regarding the x and y switch
can someone remind me why the y wouldn't go on top?
is that because we are not dividing by 1/y?
he says to not put it in only the numbers after it.
@mighty onyx what?
@nova wedge taken channel, please move
@viscid thistle I'm sorry? Where do I move to?
yeah like it's set up ln A, A= BLANK
or Log A, A= Blank
here is an example
I need to rewrite $ \log_2x + 5\log_2y +-3\log_2z$
Albot1288:
and the right answer for some reason is $xy^5/z^3$
Albot1288:
Al𝟛dium:
And that's it
The log doesn't get removed
And if it really shows (xy⁵)/(z³) as an answer, the book is wrong
@mighty onyx
I am trying to think of what he put for the fraction exponent
They also even note: ln is not part of your answer
because it should be ((1+x^2)x^1_2/sin(x))
Wdym by _2?
Albot1288:
They have x^1_2 as an answer?
how do you do fraction exponents
x^(1/2)
Not x^1/2
Is that where you fell off
Probably yeah
You should have written x^(1/2) and not x^1/2
yep I changed the whole answer to $(1+x^2)x^(1/2)/(sinx)$
Albot1288:
On latex it is x^{1/2} or x^{\frac12}
I think he did this problem wrong because wouldn't $Log_5(125)=3$
It makes a lot of sense that $\frac12$ would work, and yet I never realized it
Ah, otherwise it looks like a different function
okay so I think he typo'd because all the other ones I put were right but it says it's wrong. What if he put like 2 lol
Wdym by what if he put like 2
#books-old or #book-recommendations for help on books
as a typo idk what he put
know this one has me confused to
Use the Laws of logarithms to rewrite the expression $\ln\left(\frac{x^4\sqrt{x-1}}{3x-14}\right)$ in a form with no logarithm of a product, quotient or power. After rewriting we have $A\ln x+B\ln(x-1)+C\ln(3x-14)$
Albot1288:
we need to find A,B, and C
Yeah
So basically wants you to use the $$\log(a\cdot b)=\log(a)+\log(b)$$
$$\log(\frac{a}{b})=\log(a)-\log(b)$$
Al𝟛dium:
@mighty onyx
$\log(ab³)=A\log(a)+B\log(b³)=\underbrace{1}{A=1}\log(a)+\underbrace{3}{B=3}\log(b)$
This is an example of how it'd be done
forgot a $
True
Al𝟛dium:
Because you know $\log(a^b)=b\log(a)$
Al𝟛dium:
I'm still here just trying to work it out now
okay so a=4 b=1/2 and c=-1
Correct. @mighty onyx

would we use the same way for $\log_2\left(32(a+1)^{-4}\right)$ rewritten as
Albot1288:
$A+B\log_2(C)$
Albot1288:
for B it's -4
Yes
but what happens to the 32?
Al𝟛dium:
32 in terms of 2? like 16
81 in terms of 3 would be 3³
32 in terms of 2? like 16
32 can be expressed in a way where the 2 is the base raised to some number
As i did with 81
oh so it would be for 32 2^5
Yes.
and know c
Do you know how to continue remembering that $\log_a(a)=1$
Al𝟛dium:
After doing 32=2⁵, $\log_2(2⁵)=5\underbrace{\log_2(2)}_{1}=5$
Al𝟛dium:
You can use your logic to know why log_2(2) is 1, think of it this way, to what should you raise 2 to receive 2 as an answer.
@mighty onyx
yeah
All good then?
Find the solution of the following equation whose argument is strictly between 180 degrees and 270 degrees.
Round your answer to the nearest thousandth.
$z^5=-243i$
Rubidinium:
I'm not really sure of how I would do this
I think the modulus would be -3 though
as for the angle I have no clue
@olive quartz Hint: $-i = e^{i\cdot 270^{\circ}}$
jedben2:
Can i get help with deriving powers?
what
Do you know euler's formula?
$re^{i\theta}$
Rubidinium:
yeah
radians is better than degrees here
@viscid thistle I am still having trouble finding c
how can we use the formula here?
oops sorry
If you look on the complex plane, $-i$ is $270^{\circ}$ anticlockwise rotation from the center and has a magnitude (length) of 1 from the center. Therefore it can be written as $e^{i \cdot 270^{\circ}}$
oh
jedben2:
Ill let you figure out the rest of how to do the question 🙂
np
@viscid thistle I am still having trouble finding c
@mighty onyx repost it
$ \log_2\left(32(a+1)^{-4}\right)$
Albot1288:
$A+B\log_2(C)$
Albot1288:
wait you can't find C? it is pretty much the same as the other ones we've done
let's see if it gets clarified with this
remember what we said $\log(a\cdot b)=\log(a)+\log(b)$ right so on this case, a and b are: $$\log_2(\overbrace{32}^{a}\cdot \overbrace{(a-1)^{-4}}^{b})$$
Al𝟛dium:
what?
is*
okay
would you be able to express this as a sum of logarithms $\log(4\cdot u^{3})$?
Al𝟛dium:
@mighty onyx
$\log4 + 3\logu$
Albot1288:
\log
Albot1288:
Compile Error! Click the
reaction for details. (You may edit your message)
$\log(4)+3\log(u)$
RokettoJanpu:
yeah thx
$\log(a\cdot b)=\log(a)+\log(b)$ using a substitution with the $u:= a-1$
$$\log_2(32\cdot \overbrace{(a-1)^{-4}}^{u^{-4}})=\log(32\cdot u^{-4})$$ would you be able to express this as a sum of logarithms
Al𝟛dium:
$\log 32 and -4\log (a-1)$
Albot1288:
replace the "and" with a sum and you just found C
and well, simplify the log(32) too
I'm still confused I think
how can the constant be the sum of log(32) and -4log(a-1)
yeah
$A+B\log_2(C)$ doesn't this have a similarity with what you just said
Al𝟛dium:
you just said correctly $\log_2(32)+ -4\log_2(a-1)$
Al𝟛dium:
yeah but how can we combine them?
${\color{green}{A}}+{\color{blue}{B}}\log_2({\color{red}{C}})$
$\ {\color{green}{\log_2(32)}}+ {\color{blue}{(-4)}}\log_2({\color{red}{a-1}})$
wdym by combine?
so C would be a-1
Al𝟛dium:
yes!
fuck my teacher I had tried that like an hour ago but the page says it's wrong
huh
Albot1288:
@obsidian monolith
thanks
when doing approximation with.
$\log_b(2)=0.271, \log_b(3)=0.429, and \log_b(5)=0.629.$
Albot1288:
trying to find $\log_b(25b^3)$ should be using power rule right?
Albot1288:
not only power rules
I know for $log_b(10)$ you break it down into $\log_b(2*5)$ then into $\log_b(2) + \log_b(5)$
Albot1288:
Albot1288:
ooh wait a minute unless we get $25b_3$ by $3\log_b25$ I think
Albot1288:
what is logb(b^3)
For the $\log_b(25b³)=\log_b(25)+\log_b(b³)$ you can use this
Al𝟛dium:
ok so we would do $(\log_b(5) + \log_b(5)) + \log_b(b^3)$
Albot1288:
you can further simplify if you like
ooh wait log rules $\Log_b(b)^x=x$ right
Albot1288:
Compile Error! Click the
reaction for details. (You may edit your message)
so it would be $0.629 + 0.629 + 3$
Albot1288:
and yeah
would also look better to write 2 * logb(5) + 3
@novel cargo 
$10^{2\log5}$
^{}
Albot1288:
thx, and how would we evaluate this?
is log base 10?
2log5 = log(5*10)
?
yes
doesn't help, sorry
10 is base default
I'm assuming
2log(5)=log(5^2)
if nothing is written its usually 10
Could also be e
e is for ln
I meant 2 log 5 = log(5*2) = log(10) = 1
doesnt 2 log 5 mean log 5^2
oh, man
e is for ln
In higher math log base 10 is so useless that log is usually base e
I'm in college rip
but back to the problem, would we need to turn it into $\log5^2$ then get that and raise 10 to the power of what we get?
Albot1288:
agree
which is asking what should we raise 10 to to get 25
take 10 to that power
which gives 25
someone write please the algebra and rules
ahhh thanks
I can't rememebr them
How about $\log(30)\approx 1/2$
HoboSas:
$log(25)\approx \log(30)\approx 3/2\approx 1 \approx x \forall x\in \mathbb{N} $
log30=1+log3>1>1/2
do u mean 3/2
lol that would have been some serious engineering approximations
HoboSas:
Cursed
$ \ln\left(\frac{a^2}{b^{-4}c^{-1}}\right)=$ expanded is $\ln(a)^2 - \ln(b)^-4 +\ln(c)^-1$ right?
what is that green thing
$log(25)\approx \log(30)\approx 3/2\approx 2 \approx 3 \approx 4 \approx 10000000000$
Δφ:
Albot1288:
ln(a^2) - ln(b^4) - ln(c)
Wait base is 10
taking the powers out of parenthesis means something else
sorry, ln(a^2) + ln(b^4) + ln(c)
wouldn't be ln(c^-1)
Which is 2ln(|a|) + 4ln(|4|) + ln(c)
either -ln(c^-1) or ln(c^1)
from denominator to nominator power changes sign
but it becomes a multiplication and not division anymore
so its subtraction and not addition
so if a=2 b=3 and c=5 then we plug them in to find the answer right
I keep getting ln(1620) is that what yall are getting?
Is 1620=2^2x3^4x5?
yes
Correct
so I should be getting 1620? because it says it's wrong
but it says it's still wrong
Try evaluating it using a calculator
Boris
that's my bad



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