Question

Calculate the dy/dx. You need not expand your answers. Help with more derivatives please!! >_<

y = (8.43x^-0.1 - 0.5x^-1) / (3.4+x^2.2)

Answer 1

I know to use the derivative quotient rule, but every time I work through this problem, I keep coming up with the wrong answer. So I don't know if I'm plugging it in wrong, or if I'm messing up on the simple math part.

Answer 2

The decimal powers are laughing at me . . .

Answer 3

with their shiny negative symbols . .

Answer 4

yesh, that is how I started mine out O_O

Answer 5

Oh man, mine didn't come out like that . . . wait I'm confusing myself.

Answer 6

oh wait nvm i'm so dumb, you hadn't solve it through yet. But yes thats what I did!! I hope I did the math right.

Answer 7

(-.843x+.5x^-2)(3.4+x^2.2) - (8.43x^-0.1 - 0.5x^-1)(2.2x^1.2) / (3.4+x^2.2)^2

Answer 8

sorry mine doesn't look as neat as yours, thats how it came out when I solved through the math

Answer 9

oof -.843x^-1.1*****

Answer 10

all these numbers confuse me so badly, it's hard to keep up with it all >_<

Answer 11

k now I'm stuck Q_Q

Answer 12

Help . . .

Answer 13

\[\frac{dy}{dx}=\frac{(8.43(-0.1)x^{-0.1-1}-0.5(-1)x^{-1-1})(3.4-x^{2.2})-(0+2.2x^{2.2-1})(8.43x^{-0.1}-0.5x^{-1})}{(3.4+x^{2.2})^2} \]
\[\frac{dy}{dx}=\frac{(-0.843x^{-1.1}+0.5x^{-2})(3.4+x^{2.2})-(0+2.2x^{1.2})(8.43x^{-0.1}-0.5x^{-1})}{(3.4+x^{2.2})^2}\]

Answer 14

Yeah, I've gotten that far; but I'm not sure what to do after that.

Answer 15

what do you want to do?

Answer 16

Solve it so I don't have to look at the problem anymore ever again!!

Answer 17

well we already found y'

Answer 18

does your teacher want you to distribute on top or something and the combine any like terms if any exist?

Answer 19

But don't I have to simplify?? O_O

Answer 20

if it says to simplify then you have to find a way to do that
but if it doesn't say simplify you are done

Answer 21

I know I don't have to simplify the denomiinator, but I have to combine like terms I guess for the numerator.

Answer 22

denominator*** sorry

Answer 23

nevermind, its the stupid like terms and math where I keep messing up, the supposedly easy part. I will just try to figure it out again later I guess.

Answer 24

\[\frac{dy}{dx}=\frac{(-0.843x^{-1.1}+0.5x^{-2})(3.4+x^{2.2})-(0+2.2x^{1.2})(8.43x^{-0.1}-0.5x^{-1})}{(3.4+x^{2.2})^2}\]

------------------------------
\[(-0.843x^{-1.1}+0.5x^{-2})(3.4+x^{2.2})\]

\[(-0.843x^{-1.1}+0.5x^{-2})(3.4)+(-0.843x^{-1.1}+0.5x^{-2})(x^{2.2})\]
\[-0.28662x^{-1.1}+1.7x^{-2}+(-0.843x^{-1.1+2.2})+0.5x^{-2+2.2}\]

Answer 25

-----------------------------
\[(0+2.2x^{1.2})(8.43x^{-0.1}-0.5x^{-1})\]


\[(2.2x^{1.2})(8.43x^{-0.1}-0.5x^{-1})\]

\[18.546x^{1.2-0.1}-1.1x^{1.2-1}\]

Answer 26

\[\frac{dy}{dx}=\frac{-0.28662x^{-1.1}+1.7x^{-2}-0.843x^{1.1}+0.5x^{0.2}-(18.546x^{1.1}-1.1x^{0.2})}{(3.4+x^{2.2})^2}\]

Answer 27

\[\frac{dy}{dx}=\frac{-0.28662x^{-1.1}+1.7x^{-2}-(0.843+18.546)x^{1.1}+(0.5+1.1)x^{0.5}}{(3.4+x^{2.2})^2}\]

Answer 28

\[\frac{dy}{dx}=\frac{-0.28662x^{-1.1}+1.7x^{-2}-19.389x^{1.1}+1.6x^{0.5}}{(3.4+x^{2.2})^2}\]

Answer 29

if you really want to "simplify more" you need to multiply top and bottom by
\[x^{3.1}\]

Answer 30

\[\frac{dy}{dx}=\frac{-0.28662x^{2}+1.7x^{1.1}-19.389x^{4.2}+1.6x^{3.6}}{x^{3.1}(3.4+x^{2.2})^2}\]

Answer 31

Gruesome. Kudos to you myininaya.

Answer 32

i didn;t want to do it lol

Answer 33

I really don't like these sorts of calculations, so messy!

Answer 34

there is no way i'm checking my work
i will leave that to you riley

Answer 35

lol sorry

Answer 36

I'm trying to work back through it too, taking me a few minutes though . . . just a sec >_<

And thank you for working through it like that myininaya, I know it's very time consuming, so thank you.

Answer 37

well i don't like doing these types because a mistake is so easy to make

Answer 38

if i was your instructor i would not have asked you to simplify something like this

Answer 39

likes james said this is a monster

Answer 40

I know, I don't think anyone in my class has gotten this problem correct yet. I have to switch rooms though, but I'm gonna go to the computer lab and work on homework. So I will be right back. Almost done working through it, I keep messing up though . . . uuughh. Be right back. >_<

Answer 41

And thank you again Myininaya, very very very much.

Answer 42

np lol

Answer 43

Lol, you got it correct Myininaya!! It took me a little while to work through it all, and I had to go back and check over everything a bunch, but in the end I came up with the same thing you did (finally) and I put that answer in and it's correct!!! Thank you so very very very very much Myininaya; I think thats the toughest problem I've had to do all year, and your help was VERY much appreciated. *hugs* <3