Hard differentiation (1 Viewer)

Bdogz

Member
Joined
May 7, 2008
Messages
152
Gender
Male
HSC
N/A
whats the derivitive wiht respect to x of ln(y-x) , i think u use implicit differentiation but i dont know how to do it
 

tommykins

i am number -e^i*pi
Joined
Feb 18, 2007
Messages
5,730
Gender
Male
HSC
2008
-1/ln(y-x)

you treat the y as a constant.
 

Bdogz

Member
Joined
May 7, 2008
Messages
152
Gender
Male
HSC
N/A
Let dy/dx = y'

Therefore the derivative with respect to x of ln (y-x) would be:

oh k so wat wud be the derivative with respect to x of this equation : y=x^siny + x

i got 2 this step but im nto sure how much of it is right: dy/dx=(lnx.cosy.dy/dx + siny.1/x).e^sinylnx + 1
 
Last edited:

tommykins

i am number -e^i*pi
Joined
Feb 18, 2007
Messages
5,730
Gender
Male
HSC
2008
is that y = x^siny + x or z= x^siny + x?

if the latter, dz/dx = x^sin(y)*sin(y)/x+1
 

Bdogz

Member
Joined
May 7, 2008
Messages
152
Gender
Male
HSC
N/A
is that y = x^siny + x or z= x^siny + x?

if the latter, dz/dx = x^sin(y)*sin(y)/x+1
its a completely different question to the 1st thing i posted on here sorry, so the question is find dy/dx of y=x^siny + x
 

tommykins

i am number -e^i*pi
Joined
Feb 18, 2007
Messages
5,730
Gender
Male
HSC
2008
yeah i was curious as to why they had to do it.

not like its hard either lol
 

Drongoski

Well-Known Member
Joined
Feb 22, 2009
Messages
4,249
Gender
Male
HSC
N/A
Is it: y = xsin y + x ??

If so, is the answer ??




Edit: corrected: it's cos y not cos x; my typo.
 
Last edited:

Bdogz

Member
Joined
May 7, 2008
Messages
152
Gender
Male
HSC
N/A
Is it: y = xsin y + x ??

If so, is the answer ??


on the bottom line in denominator i got cosy instead of cosx, but apart from that i got wat u got, i dont hv the answer on me but once i get it ill notify u thanks

NB i shudve put this in the tertiary forum sorry
 
Last edited:

-Onlooker-

Member
Joined
Mar 15, 2009
Messages
150
Gender
Male
HSC
2009
Functions of several vairables is not in the HSC, hence partial derivatives is beyond the scope of the syllabus.

You sure?

iirc; one of the hsc papers asked us to differentiate or integrate cos (x - y ). It was in the earlier years.

edit: It might not have asked us directly; might have been in the solutions, I can't remember 100% sorry.
 

Iruka

Member
Joined
Jan 25, 2006
Messages
544
Gender
Undisclosed
HSC
N/A
There seems to be quite a bit of confusion of partial differentiation with implicit differentiation in this thread.

Implicit differentiation is in the syllabus; partial differentiation is not.
 

jchoi

Member
Joined
Nov 16, 2007
Messages
50
Gender
Male
HSC
2009
How does y = xsin y + x ?? turn into
?

Can someone show me the steps please? :)
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top