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how to diffeniate this

cos(e^xy).y(e^xy)


with respect to x


Tried for 1hr :frown:

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Reply 1
You cant differentiate that, it's not an equation
Original post by Chinese Noodles
cos(e^xy).y(e^xy)


with respect to x


Tried for 1hr :frown:


Implicit differentiation.
Thats not possible. Theres too many variables, thats not taught in A-Level.
Reply 4
Original post by Epinerphine
Thats not possible. Theres too many variables, thats not taught in A-Level.


It is A level.
Original post by Epinerphine
Thats not possible. Theres too many variables, thats not taught in A-Level.


Yes it is.
Reply 6
Original post by Chinese Noodles
cos(e^xy).y(e^xy)


with respect to x


Tried for 1hr :frown:

First use product rule to give
ddx(cos(exy)yexy)=ddx(cos(exy))yexy+ddx(yexy)cos(exy) \displaystyle \frac{d}{dx} \left ( \cos (e^{xy})\cdot ye^{xy} \right ) = \frac{d}{dx} \left (\cos (e^{xy}) \right ) \cdot ye^{xy} +\frac{d}{dx} \left (ye^{xy} \right ) \cdot \cos (e^{xy}) then differentiate implicitly.
Remember that d/dx(f(y))=dydxddy(f(y)) d/dx (f(y)) = \frac{dy}{dx} \cdot \frac{d}{dy} (f(y)) .
(edited 7 years ago)
Original post by Chinese Noodles
cos(e^xy).y(e^xy)


with respect to x


Tried for 1hr :frown:


I got the answer to be:

dydxexycos(exy)[xy+1]+yexy[ycos(exy)sin(exy)]\frac{dy}{dx} e^{xy}cos(e^{xy})[xy+1]+ye^{xy}[ycos(e^{xy})-sin(e^{xy})]

Someone verify; I dont even care if I'm wrong. Slap whoever gave you this. Good night and good luck with it! :sleep:
(edited 7 years ago)
Original post by GUMI
You cant differentiate that, it's not an equation


Of course you can!
Yh proper impossible.
what even is e^xy. It duznt even make sense rn. Wut the hell.
Zacken where r u. Need yr help.



Posted from TSR Mobile
Ay I solved it, last night's attempt was incorrect.

it's so ez op, primary school stuff, pffft

Spoiler

(edited 7 years ago)
Original post by RDKGames
Ay I solved it.

it's so ez op, primary school stuff, pffft

BS.
Did u use the quadratic formula.
I might complete the square but i forgot


Posted from TSR Mobile
Original post by physicsmaths
BS.
Did u use the quadratic formula.
I might complete the square but i forgot


Posted from TSR Mobile


QF? lol for what?
Original post by RDKGames
QF? lol for what?


Quadratic formula always works.
It always gives answers doesnt it.
So i thought if it guves solutions i just use it on this and answer will come.


Posted from TSR Mobile
Original post by physicsmaths
Quadratic formula always works.
It always gives answers doesnt it.
So i thought if it guves solutions i just use it on this and answer will come.


Posted from TSR Mobile


Don't forget the plus and minus signs when square rooting then you should get some very neat answers to this indeed.
Reply 15
Original post by GUMI
You cant differentiate that, it's not an equation


I guess you disagree with d/dx (x) = 1 then? Since x isn't an equation...

Honestly.

Original post by Epinerphine
Thats not possible.


Wrong. It is.

Theres too many variables


Wrong. There isn't.

thats not taught in A-Level.


Wrong. It is.
Reply 16
Original post by Zacken
I guess you disagree with d/dx (x) = 1 then? Since x isn't an equation...

i was just going off the fact that there is no equal sign :hoppy:
Original post by GUMI
i was just going off the fact that there is no equal sign :hoppy:


Why do you assume there must be an equals sign?
Reply 18
Original post by GUMI
i was just going off the fact that there is no equal sign :hoppy:

...your point is?
Reply 19
Does anyone else think people often have misconceptions about differentiating and using wrong notation/not fully understanding it. Are schools to blame?
Like you see dydx(x)=1 \frac{dy}{dx} (x)=1 .

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