Point moving along the curve y=2x^2+1

[mattsoto]

A point moves along the curve y=2x^2+1 in such a way that the y value is decreasing at the rate of 2 units per second. At what rate is x changing when x=(3/2)?

 

[amcavoy]

A point moves along the curve y=2x^2+1 in such a way that the y value is decreasing at the rate of 2 units per second. At what rate is x changing when x=(3/2)?

What have you done so far? Do you know anything about related rates? Start by differentiating, then use the fact that:

\frac{dy}{dx}=\frac{\frac{dy}{dt}}{\frac{dx}{dt}}

Try writing the info. given in terms of derivatives.

Alex

 

[Galileo]

What is the given and what is the unknown? From the problem statement, you know that y and x are also functions of t.
Show what you got so far.