# Thread: 1st and 2nd deriviative

1. ## 1st and 2nd deriviative

Can someone help me find the first and second derivative of this function. I did it but my answer had a ton of decimals. (something like 2048x^3 -15656.84 etc...)

2. Originally Posted by lilwayne
Can someone help me find the first and second derivative of this function. I did it but my answer had a ton of decimals. (something like 2048x^3 -15656.84 etc...)
Put $\displaystyle k = 3.2$ and $\displaystyle t = 10.24$, now find the first and the second derivative of $\displaystyle \frac{4x-k}{(4x-t)^2}$
When you've done that, put $\displaystyle k$ and $\displaystyle t$ back to their values. Does that make it easier?

3. Use the quotient rule, what did you get?

4. i have to simplify it down because i gotta do curve sketching but i'm having problems

5. Show some working my friend, where are you stuck?

$\displaystyle \displaystyle g'(x) = \frac{(4x-10.24)^2(4x-3.2)'-(4x-3.2)((4x-10.24)^2)'}{[(4x-10.24)^2]^2} = \dots$

6. yeah i got that, oh whoops the teacher said no factoring lol...

I have g'(x) = 4(4x-10.24)^2 - (4x-3.2)*2(4x-10.24)(4)

but i'm supposed to solve this.. and i don't know how

7. Just do it slowly, step by step using the product/quotient rule.

If you're having trouble using the quotient rule, you can rewrite the function as (4x-3.2)(4x-10.24)^(-2) and solve using the product rule instead.