The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

Differentiating wrt x

is this the same?

xy=c^2
dy/dx= -c^2x^-2

and xy=c^2
dy/dy= -y/x
Reply 1
Avatar for Zacken
Zacken
22
Original post by Acrux
is this the same?

xy=c^2
dy/dx= -c^2x^-2


This is fine.



and xy=c^2
dy/dy= -y/x


This is also fine if you meant dy/dx and not dy/dy.
Reply 2
Avatar for Acrux
Acrux
OP
7
Original post by Zacken
This is fine.





This is also fine if you meant dy/dx and not dy/dy.


Yes i meant that.
So either working is fine they both give same gradient
Reply 3
Avatar for Zacken
Zacken
22
Original post by Acrux
Yes i meant that.
So either working is fine they both give same gradient


Yeah.
Reply 4
Avatar for nerak99
nerak99
13
Original post by Zacken
Yeah.


It might be as well to check the question as it may well say to give dy/dx in terms of x. In which case only one of your answers is fine.
Reply 5
Avatar for Zacken
Zacken
22
Original post by nerak99
It might be as well to check the question as it may well say to give dy/dx in terms of x. In which case only one of your answers is fine.


It's most a question of "find the tangent to the parabola y = 4ax at P" in which case, either form doesn't matter.
Reply 6
Avatar for nerak99
nerak99
13
Well I didn't see the OP quote the question or are you just guessing? It could be just a Core 4 implicit differentiation Q1i could it not?
what is this ****
Reply 8
Avatar for Zacken
Zacken
22
Original post by nerak99
Well I didn't see the OP quote the question or are you just guessing? It could be just a Core 4 implicit differentiation Q1i could it not?


Possibly, but given that the OP asked about FP1 a few hours ago and this is pretty much the equation of a hyperbola, I highly doubt it. Plus I don't think they'd put something about a hyperbola in C4 since it's give those who do FP1 an unfair advantage.
Reply 9
Avatar for nerak99
nerak99
13
Well Hyperbola is not on C4 as such but I think cross-referencing previous posts is, as the lawyers say, "too remote" ,to be a defence against overstating your certainty in your post earlier. :smile: <<< a very rare emoticon from me!
Reply 10
Avatar for Acrux
Acrux
OP
7
Original post by nerak99
Well Hyperbola is not on C4 as such but I think cross-referencing previous posts is, as the lawyers say, "too remote" ,to be a defence against overstating your certainty in your post earlier. :smile: <<< a very rare emoticon from me!


Correct.
Tis FP1.

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you