(4 pts) 8) Briefly explain what is wrong with the following attempt to find the concavity of the parametric curve J x=+3+1 I y= t2 - t x'(t) = 3t2 and x"(t) = 6t y'(t) = 2t - 1 and y"(t) = 2 So the second derivative is y"(t) = *" (t ) = This second derivative is negative for t 0 so the curve must be concave down for t 0