Put Your Calculus Hat On (Help)

[Toaster]

The Problem

y=((X+1)/(X-1))^4

Chain Rule + Quotient Rule:

y'=4((X+1)/(X-1))^3 (((1)(X-1)-(1)(X+1))/((X-1)^2))

Combining the terms, I get:

y'=-8((X+1)^3)/((X-1)^5)

BUT the book says(Notice the lack of negative):

y'=8((X+1)^3)/((X-1)^5)

So where did I get (Or lose) The negative.

There will probably be more questions farther on. I realize that It is hard to look at it in this form so maybe writing it out will help.

Thanks anyone!

Edit: I Think it MIGHT be a book typo.

 

[daguin]

CALCULUS HAT ! :undecided:

I don't even have an arithmetic hat :na:

Peace,
dave

 

[Toaster]

Lol come on. This is a science forum, some few here have to know a little.

 

[Ezcal]

WolframAlpha and I agree with you, Toaster. It's a book typo.

WolframAlpha's Work Here

 

[Tonga]

It's been a looonnnggg time man but the negative just doesn't evaporate. I agree with you on the typo!

 

[Toaster]

Thanks, I thought I was going crazy. I have few more that I had no idea how to go about solving. The back of the book has the asnwers but not how to get them.

Here is one:
y=(cot(x^5))^7

y'=30x((1+(((x^2)+2)^5))^2)(((x^2)+2)^4)

Talk about parenthesis madness!!!

You don't have to show the solving, just what rules in what steps... (Thats what has got me tied up.)

If anyone knows a site that shows how to solve I would be EXTREMELY grateful.

Thanks

 

[Ezcal]

Well, we never had to deal with cot, csc or sec in my calc class, but it looks like you'd want to start with the chain rule, since you have a function (x^5) inside another function there.

WolframAlpha, by the way, is a great resource for basically all math problems. You basically plug in what you want... "derivative of (cot(x^5))^7" and it will spit out the answer. Most of the time you can even hit "Show Steps" and it'll walk you through how to solve it.

 

[Toaster]

K I will look it up. What confuses me is that the Wolf, and book answer are different, even though the Wolf answer looks a lot more reasonable.

 

[swimminsurfer256]

TI-89


nuff said. that got me through calc BC all those years ago