Originally Posted by

**nycmath** Find the rate of change of the distance between the origin and a moving point on the graph of

y = x^2 + 1 It dx/Dr = 2 cm/second

My work:

I proceeded taking the implicit derivative of the given function to find dy/dt.

dy/dt = 2x* dx/dt

dy/dt = 2x* (2) and the I plugged x = 0 from the origin value for x.

dy/dt = 2(0)* (0)

dy/dt = 0...My Answer.

Book's Answer:

2(2x^3+3x)/sqrt(x^4+3x^2+1)

My Answer is zero and the book's answer is a crazy rational function.

Can someone answer this question?