You are Here: Home >< Maths

1. x = 1 + (lny)/(ln5)

find dx/dy

i have got as far as saying using the quotient rule, lny = u, ln5 = v

so ln5(1/y) - nothing as ln5 = 0, times lny = 0.. or do you just write lny?
divided by ln5^2

so in summary, i have got ln5(1/y)/(ln5)^2

is this right?? I am confused plz help guys!!

+ rep thanks!
2. (Original post by desertwarrior)
x = 1 + (lny)/(ln5)

find dx/dy

i have got as far as saying using the quotient rule, lny = u, ln5 = v

so ln5(1/y) - nothing as ln5 = 0, times lny = 0.. or do you just write lny?
divided by ln5^2

so in summary, i have got ln5(1/y)/(ln5)^2

is this right?? I am confused plz help guys!!

+ rep thanks!

in5 is a constant.

The differential of Iny is 1/y
3. (Original post by steve2005)
in5 is a constant.

The differential of Iny is 1/y
ah k, so when differentiating the u (dv/dx)
it is just 0 times lny which is 0?
4. ^ What he said. ln5 can be taken as a constant and can be written as

1/ln5 *lny.
5. ahhh i get it now thansk guys!!!!!

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: January 18, 2010
Today on TSR

How do you think you'll do?

### University open days

Wed, 25 Jul '18
2. University of Buckingham
Wed, 25 Jul '18
3. Bournemouth University
Wed, 1 Aug '18
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams