Mathematics

Problem

For a parametric curve

x=f(t),\,y=g(t)

with

f'(t)\neq0

, the second derivative is negative on an open interval

I

. What does this indicate about the shape of the curve on

I

? a) It has a point of inflection at every point of

I

. b) No conclusion can be drawn about concavity from this information. c) It is concave downward on

I

. d) It is concave upward on

I