For the equation given below, evaluate dy/dx at the point (-1,2).

(3x^2)-(3xy)+(y^3)=17

Question

For the equation given below, evaluate dy/dx at the point (-1,2).

(3x^2)-(3xy)+(y^3)=17

anonymous · Answer

i just did this problem in my math homework haha

anonymous · Answer

hahaha o gosh webwork?!

anonymous · Answer

so i just realized i did it wrong in my stuff haha. im gonna try and redo it now lol

baldymcgee6 · Answer

Did you get it or do you still need help?

anonymous · Answer

o i still need help! thank you!

baldymcgee6 · Answer

Okay, so we have to differentiate this implicitly, do you know what that is?

anonymous · Answer

yes! i get -4x+3y/-3x+3y^2

anonymous · Answer

but i don't get it from there....!

baldymcgee6 · Answer

I think you're derivative is wrong...

baldymcgee6 · Answer

your*

anonymous · Answer

i dont get it! please help

baldymcgee6 · Answer

okay... here we go

anonymous · Answer

thank you!

baldymcgee6 · Answer

anonymous · Answer

does that mean i can just plug in (-1,2) for x and y? because i get 4/3 and it says thats not correct!

baldymcgee6 · Answer

hmm, you should just be able to plug those in...

anonymous · Answer

$$\frac{dy}{dx}=\frac{2 x-y}{x-y^2} $$$$\frac{4}{5} \text{at } (-1,2) $$

anonymous · Answer

o thank you @robtobey! do u mind writing out the steps, im having trouble as to how u arrived to that. thanks so much!

baldymcgee6 · Answer

@tenistaego my original solution just missed a y^2 in the denominator, this should be correct and equivalent to robtoobey's

anonymous · Answer

thx@baldymcgee6!

baldymcgee6 · Answer

No problem, please choose the appropriate best answer :)

anonymous · Answer

A solution using Mathematica for the calculations is attached.

anonymous · Answer

THANK YOU!

anonymous · Answer

Your are welcome.