I'm assuming you meant "Find where
"
Is that correct? If so, what would be the first step?
Yes. Rather than do that problem for you, let me find the second derivative of y when .
Differentiating once, . Differentiating again, . Now, you can solve for y'':
.
You could, now, replace y' from the first derivative but typically, that is not necessary.
as i retry this... Im workin on finding the formula for dy/dx
and i got to here... 3x^2+[x(dy/dx) + y(dx/dx)]+2y=0
now, the stuff in the brackets.. how do I simplify that... in the first term can I 'cancel' the x leaving y in the numerator. but then that leaves the second term...
No, you can't cancel inside the brackets. The symbol is one symbol. It is not a fraction. However, the , so that simplifies a bit. Incidentally, I would agree with your differentiation except for the last term. You should use the chain rule on it thus:
Can you continue?