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C3 Differentiation watch

1. Need help to differentiate this :

3e^x - 1/2lnx - 2

So differentiating the first term will give : 3e^x

How about the second one ? -1/2lnx, how exactly do I differentiate that ?
2. y = 1/2 ln x
dy/dx =
1/2
---
x
3. (Original post by uer23)

How about the second one ? -1/2lnx, how exactly do I differentiate that ?
Is it -1 / 2lnx or -0.5lnx ?
4. Use Chain Rule. And from then, by inspection.
5. differentiate 2lnx separately if that makes it any easier then flip the fraction
6. EDIT: Disregard this I am an idiot
7. (Original post by Andylol)
y = 1/2 ln x
dy/dx =
1/2
---
x
Right so it's
8. 3e^x - 1/2x

jst differentiate lnx then multiply by -0.5
9. (Original post by JeevesTSR)
Is it -1 / 2lnx or -0.5lnx ?
-0.5lnx.
10. (Original post by uer23)
-0.5lnx.
ok then i think its -0.5 * 1/x

= -1 / 2x
11. (Original post by uer23)
Right so it's
correct
12. So related to this question...

The differential of the curve

is as stated above

The curve f(x) has a turning point at p, the x co-ordinate of p is

Show that

So far what I've done

So what do I do know take the natural log of both sides ? But then how is that going to get me closer to my target which I have to show.
13. Bump... +rep available.
14. you're basically there....just multiply by alpha, then divide by e^alpha and you've done it...
15. (Original post by uer23)
So related to this question...

The differential of the curve

is as stated above

The curve f(x) has a turning point at p, the x co-ordinate of p is

Show that

So far what I've done

So what do I do know take the natural log of both sides ? But then how is that going to get me closer to my target which I have to show.
All the calculations are done, just need to rearrange alpha and e^a

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