# Implicit differentiation help where help statedWatch

Announcements
Thread starter 5 years ago
#1

TY -N

Why does the 'x' disappear?
0
5 years ago
#2
(Original post by REASON_Lighters)

TY -N

Why does the 'x' disappear?
lna is a number, let's call it c.
.
Remember and so .
0
Thread starter 5 years ago
#3
(Original post by keromedic)
lna is a number, let's call it c.
.
Remember and so .
of course differentiating x gets 1 ffs. Thank you extremely clear layout and work, kind regards.

Thanks makes sense in the end ))))))
1
5 years ago
#4
(Original post by REASON_Lighters)
of course differentiating x gets 1 ffs. Thank you extremely clear layout and work, kind regards.

Thanks makes sense in the end ))))))
Don't mention it. Quite often it's these things that cost us the marks
0
Thread starter 5 years ago
#5
(Original post by keromedic)
Don't mention it. Quite often it's these things that cost us the marks
idd :P

I take it you're doing A2 Maths atm, do you do FM as well?
0
5 years ago
#6
(Original post by REASON_Lighters)
idd :P

I take it you're doing A2 Maths atm, do you do FM as well?
I did A2 Mathematics last year. Presently, I'm studying AS/A2 Further Mathematics.
0
Thread starter 5 years ago
#7
(Original post by keromedic)
I did A2 Mathematics last year. Presently, I'm studying AS/A2 Further Mathematics.
Very good, me too except I am doing a2 maths this year as well :_)

Sorry to trouble you but I have another question:

R=200(0.9)^t Find the value of dR/dt when t=8

I get dR to be =(200*0.9^t)

But I dont get why you have to multiply by ln 0.9 with my dR
0
5 years ago
#8
(Original post by REASON_Lighters)
Very good, me too except I am doing a2 maths this year as well :_)

Sorry to trouble you but I have another question:

R=200(0.9)^t Find the value of dR/dt when t=8

I get dR to be =(200*0.9^t)

But I dont get why you have to multiply by ln 0.9 with my dR
I'm happy to help but do you mind latexing or scanning your question and attempted working?
0
Thread starter 5 years ago
#9
(Original post by keromedic)
I'm happy to help but do you mind latexing or scanning your question and attempted working?
yeah sure sorry:

Well the question is short - and involves product rule, its just that I don't get the 'In 0.9' from the product rule.
0
5 years ago
#10
(Original post by REASON_Lighters)
yeah sure sorry:

Well the question is short - and involves product rule, its just that I don't get the 'In 0.9' from the product rule.
Sorry about the late response. Just checking it now, had to do something.
0
Thread starter 5 years ago
#11
(Original post by keromedic)
Sorry about the late response. Just checking it now, had to do something.
No problem, happy for the assistance
0
5 years ago
#12
(Original post by REASON_Lighters)
yeah sure sorry:

Well the question is short - and involves product rule, its just that I don't get the 'In 0.9' from the product rule.
I'm not sure I understand your question. You've learnt that . in this case is 0.9. What's the problem?
0
Thread starter 5 years ago
#13
(Original post by keromedic)
I'm not sure I understand your question. You've learnt that . in this case is 0.9. What's the problem?
Thank you, yeah that makes sense, so do you have to multiply by 200 with respect to the product rule as well then?
0
5 years ago
#14
(Original post by REASON_Lighters)
Thank you, yeah that makes sense, so do you have to multiply by 200 with respect to the product rule as well then?
200 is a constant so it isn't involved in differentiation. It's not a product rule thing, no.
0
5 years ago
#15
(Original post by REASON_Lighters)

TY -N

Why does the 'x' disappear?
Because has been omitted, it should be om the left hand side.
0
5 years ago
#16
(Original post by brianeverit)
Because has been omitted, it should be om the left hand side.
Ah yes, I hadn't spotted the missing [ted]\dfrac{dy}{dx}[/tex]. Why/how is that the reason?
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• SOAS University of London
Wed, 29 May '19
• University of Exeter
Undergraduate Open Day - Penryn Campus Undergraduate
Thu, 30 May '19
• Cranfield University
Cranfield Forensic MSc Programme Open Day Postgraduate
Fri, 31 May '19

### Poll

Join the discussion

#### How did your AQA A-level Business Paper 1 go?

Loved the paper - Feeling positive (163)
22.27%
The paper was reasonable (348)
47.54%
Not feeling great about that exam... (137)
18.72%
It was TERRIBLE (84)
11.48%