I have a question I was hoping someone could help me out with:

use implicite differentiation to find y' of

xy=y^3+x^3

so would it be..

(1y) + (xy') = (3y^2)y' + 3x^2

xy' - (3y^2)y' = 3x^2 - y

xy' - y' = (3x^2 - y) / 3y^2

then..?

am I on the right track here?


also, x=sin(y) find y'... would it just be cos (y)?? or do i use the chain rule?


thanks for any help, i'd appreciate it if you would explain how you come up with an answer so I can try to figure out what i'm doing also.

 

Man I dont miss that part of school at All....................

 

I Know of Y







in Y.W.C.A.

 

I'm "e" integrate me all you want!!!

 

I've been told that x=sin, but I can't help with calculus.

 

Here's your answer:

Differentiate with respect to x,

xy' + y = (3y^2)y' + 3x^2

then solve for y':

y'(x - 3y^2) = 3x^2 -y

y' = (3x^2 -y) / (x - 3y^2)

Does that help?

I'm going to leave the Trig. function up to you or you'll never learn.....

 

Alright, I can't resist, here's your Trig function...I'm a little rusty, so it may not be all right:

Differentiate with respect to x:

1 = cos(y)y'

then solve for y':

y' = 1 / cos(y)

or

y' = sec(y)

 

thanks 53, i looked a little harder at my notes and those are the answers i came up with.

i hate trig functions ughhhh

is the third differential of y=sin(3x) y'''=-27 cos (3x)?

 

I think so, y''' = -27cos(3x) is what I get.

What's your major?

 

mechanical engineering, i'd like to get into automotive engineering.

but we'll see what happens, I don't know if this college thing is for me or not just yet.

what about you?

 

Mmm, yes, Mechanical. I'm getting close to finishing my Civil Engineering degree. The math just gets worse. I remember Calc I, it wasn't too bad. Calc II was the hardest for me. Calc. III which was Multivariable Vector Calculus was pretty tough as well. Then comes Ordinary Differential Equations....and depending on how your school does it, it could be ODE with or without Matrix theory, (linear algebra). I had the ODE with matrix theory...tough class, I had to take it twice. I'm guessing you'll have to take Statistics as well .....Thing is, you take all these math classes and then you start in on the Engineering classes. I like to say that all Engineering classes are math classes. It doesn't matter what class it is, it's all numbers and calculations.

Good luck, and I hope I was right. It's been a few years since I did Implicite Differentiation

 

Calc I, Calc II, Diff Eq, Calc III............you must be an engineering student at UofI eh.

 

ok you all, this is really detering me from ever doing any college! i hate math with a passion!

 

don't worry, they only make the idiots that decide they want to be engineers do this crazy math.

 

Stick with it... You will not need to do that crap again once you get out in the real world. You need to pay your dues..

I had that stuff a few years ago when I went for Electrical Engineering degree and never used it again.. Thank God...

Differential Equations was easier than Calculus IMHO..