#Calculus
311 messages · Page 1 of 1 (latest)
wym how to solve ?
it's just computing derivatives
(although there's smarter ways than others here)
@neat granite
yeah i basically need that smarter way
focus on u * du/dx for a minute, it looks familiar eh
it's almost d(u^2)/dx
bro i can't get u
d(u^2)/dx = 2 u * du/dx is my point
same for v
so u * du/dx = 1/2 d(u^2)/dx
turns out that simplifies a whole lot of stuff here
can u pliz show me?
show what ?
i did till second order derivative but not able to get the answer
$$\dv{(u^2)}{x} = u \dv{u}{x} + \dv{u}{x} u = 2u\dv{u}{x}$$
aPlatypus
@neat granite
bro is dis a formula?
oh i c
so $u\dv{u}{x} = \frac12 \dv{(u^2)}{x}$
aPlatypus
same for $v$, $v\dv{v}{x} = \frac12 \dv{(v^2)}{x}$
aPlatypus
try and add those
ok until den can u help me with this as well?
ok
got stucked at 1 step
yeah?
Wt to do after dis?
you don't have to compute them seperately
alright I'll spell it out completely for you
\begin{align*}
u\dv{u}{x} + v\dv{v}{x} &= \frac12 \dv{(u^2)}{x} + \frac12 \dv{(v^2)}{x} \\
&= \frac12 \dv{(u^2 + v^2)}{x}
\end{align*}
aPlatypus
that 2nd line works cause the derivative is a linear operator
df/dx + dg/dx = d(f+g)/dx
bro can we do coding here?
nah this bot is only a thing that types math
oh
now u^2 + v^2 is easy to work with
still need to use uv form ryt?
it's just e^(2ax)
The final asnwer?
Formula?
no?
literally from the functions you are given
but I mean honestly if you have trouble with your algebra, I'd focus on getting better at algebra before using fancy tricks like I'm doing here
Bro i think there is a mistake in ur step
if your algebra is already shaky, you just won't notice the trick
ok which one ?
nope
e^(2ax) cos^2(bx) + e^(2ax) sin^2(bx) = e^(2ax) * (cos^2(bx) + sin^2(bx)) = e^(2ax) * 1
algebra again mate
it's just factoring
how dis step came from 1/2d(u^2+v^2)?
did u use uv?
ok got it
alright so u^2 + v^2 = e^(2ax)
that's quite easy to find the derivative of that
\begin{align*}
u\dv{u}{x} + v\dv{v}{x} &= \frac12 \dv{(u^2)}{x} + \frac12 \dv{(v^2)}{x} \\
&= \frac12 \dv{(u^2 + v^2)}{x} \\
&= \frac12 2ae^{2ax} \\
&= ae^{2ax}
\end{align*}
got it bro
aPlatypus
thanks a lot
u just said algebra so i was wondering where did the functions go
but u used trigo too
if your algebra isn't perfectly fine, you won't notice those tricks
bro how can i improve?
khan academy is prolly fine
i did till second order derivative but not able to get the answer
yeah what are the derivatives you got ?
cool bro
that question seems screwed up indeed
if anything x^2 d^2y/dx^2 + y = 0 works
,w solve y'' + y = 0
,w solve y'' = 0
,w solve x^2y'' + xy' + y = 0
oops, should have talked more slowly I guess
wt was this?
xy' = cos(logx)
xy''={-sin(logx)}/x
the 2nd one doesn't follow from the first
it does bro
I said that the question was screwed up when it wasnt
nope
you differentiated both sides
however on the right side there's a product of two functions
y' is {cos(logx)}/x
ok sure
now to differentiate again i took x to left hand side
yes
your way isn't bad either
you screwed up the execution that's all
xy' = cos(log(x))
i did according to optionsðŸ˜
so d/dx (xy') = d/dx (cos(log(x)))
on the right you get -sin(log(x))/x indeed
on the left you have a product of two functions
xy'' + y' = -sin(log(x))/x
x^2 y'' + xy' = -sin(log(x))
that's a valid deduction
bro in quotient rule i think it went more hectic
yeah it's a bit harder
this is fine though
so x^2 y'' + xy' + y = -sin(log(x)) + sin(log(x)) = 0
how bro
xy' is a product of two functions
you can't just say the derivative of xy' is xy''
as attractive as it sounds
in the option they gave this way only ryt?
I solved it already
wdym it's in the options
the option c
if you do a wrong step you'll get fucked up results that's all I'm saying
bro literally i'm not getting ur steps
you won't get option c with the way you've done it
can u pliz use pen and paper?
$$\dv{(xy')}{x} = \dv{x}{x}y' + x\dv{(y')}{x} = y' + xy''$$
aPlatypus
$$\dv{(xy')}{x} = \cos(\log(x)) - \sin(\log(x))$$
aPlatypus
yes that's true
your notations are completely wtf though
but it seems like you got it
wt to do after these now
so basically these is my y'' ?
but i was solving y'' only ryt?
want me to continue? @soft crypt
ig
i'm ok with that too
y'' ki baat ho rahi hai bhai
haan
hmm
hm
haan
wahi pe product rule lagaya
ye
lhs and rhs ko alag se calculate karni hai?
dekho jo mera y' hai wo cos(log(x)) hai na?
to maine x*cos(log(x))/x kiya
kyu ki wahi mera y' tha
Dissrupt
x *y' kiya
Bhai sorry internet server down ho gaya tha
@echo fern kya tum ho?
Fir ye aaya
Bhai dy/dx cos{log(x)} /x aya ryt
Fir x ko left hand side bhej diya
X*dy/dx=x cos{log(x)} ryt?
Kyu ki mere dy/dx hi toh cos( log( x)/x hai
Bhai come straight to the point
Kaha galti kiya wo batao
Wiase tum kaha se ho bhai
Itna badiya hindi bol rahe ho
Dissrupt
Haan yehi toh maine bhi kiya tha
Matlab(a+b) ²= a²+b²+2ab aisa nahi hai ye
Rhs lhs ka result nahi dega?
Wo toh maine bas example diya tha identity ka
Like rhs is not the result of lhs ye kehna chahte ho ryt?
Y kya hai?
Y =Sin (log(x)) na?
Bhai maine kaha galti kiya wo step batao na
Y ka value put nahi karna hai?
Ok in general ki baat kar rahe ho
Like derivative of dy/dx is d²y/dx²?
1 ayega
Okok
Dissrupt
Abhi rhs ko bhi alag se differentiate karna hai?
Got it
Product rule rhs mai bhi?
Rhs ka equation batana ekbar
Den - sin(log(x) /x
Sahi hai?
X²d²y/dx² +xdy/dx=- sin(log(x)?
Sin (log(x))
Lhs jane se y ban jayega ok
Got it
Thansk a lot
Haan bhai
Kaha se ho tum?
Maine bich se hi options ke saath match karne ki koshis ki isliye
Konsi state?
Achi baat hai Indian bhi calculus chat mai hi kr pa rahe hai
Bhai wo dusra bhai jo tha wo tumhara dost hai?
Tum phone nahi chalate?
Konsi class mai ho tum?
Oo cbse?
Pass out iss saal
Lekin bas naam ka
11 aur 12 covid mai chala gaya
Nah
Lekin manipur mai violence ho raha hai na
Isliye dadi ke ghar mai baitha hu
Algebra strong karo bol raha tha woh bhai
Kya chij strong karna hai exactly
Tumse pahele jo mukhe sikha raha tha
Haan
Yes
Lekin ab realise huwa 12 ka 20% bhi cover nahi kya hamare time mai
Nahi manipur mai hi jaakr karunga
Waise distance course lene ka soch raha hu
Abhi toh mere pass kitan nahi hai 11 ka
Pata nahi jo option milega usi ka lelunga bas degree ke liye
Toh kaha se padu bhai?
Waise woh derivative bot ko chalana sikha do na
Integration bhi hoga usse?
Kaha se?
Youtube pe nahi milenge?
Waise ncert se nahi toh kaha se padu?
Yehi bots ko chalane ka tarika
Konsi channel se?
Latex matlab?
Aaj hi naam sun rahu hu bhai
Famous nahi hai woh?
Lekin mai jee ke liye preparation nahi kar rahu hu
Wahi basic hi hila hai bhai
Corona ke time mai 11 ka pura online hi huwa
Aur 12 mai bhi maths maam ne school lately join kiya
Integration ka out of 11 exercise bas 5 the
Yh?
Oh yt bolo na
Ok
Thanks bhai
Abhi nda ka pyqs tha wo question
Ohh
Maine first time encounter kiya
Like jo general derivative hai us ka question aj tak nahi kiya tha
Isliye kuch nahi samaj mai ah raha tha
Oh
Bas 1 months baki hai ab🥶
Nda sept 3 ko hai
Isliye to pyqs kar raha tha
11th?
Sukriya
Nah nah nahi karunga
Abhi toh bas pyqs hi karta jaunga
Kaha pe?
.solved
Oo
Acha case sensitive hai🤣
Ho gaya?
.solved
Post marked as solved by @neat granite.
Use .unsolved if this was a mistake.
Ok itna advanced badiya
@soft crypt how shall i search algebra basics or algebra for calculus?
if you want a book, there's basic mathematics by serge lang which is quite alright for that (findable online not too difficultly)
if you prefer online, review the algebra part in khan academy, at least you have an infinite source of exercises there (although repetitive)
Algebra covers exponents and?
I just put basic computation in algebra in my head (i'm a bit old lol)
I guess precalculus would be more fitting to your needs rn
Wts precalculus?
In mathematics education, precalculus is a course, or a set of courses, that includes algebra and trigonometry at a level which is designed to prepare students for the study of calculus, thus the name precalculus. Schools often distinguish between algebra and trigonometry as two separate parts of the coursework.
I'm ok with trigo
it's a bit of a melting pot of algebra and common functions (trig, log, exponential, ...non-exhaustive list)
Oh