a partical moves along the curve y=(17+x^3)^1/2. as it reaches the point (4,9) the y coordinate is increasing at a rate of 4 cm/s. how fast is the x-coordinate of the point changing at that instant? so dy/dt=4 cm/s i diffeientate the curve equation with respect to time to get dy/dt=(3x^2/2(17+x^3)^1/2)dx/dt i want to find dx/dt so i put 4 cm/s in for dy/dt and 4 for x (given by the point (4,9)) and then i solve for dx/dt, but i am not coming up with the right answer. please tell me what i am doing wrong.