Question

A point moving on the graph of y2-4x2=12 so that the x coordinate is decreasing by 2 units per second when (x.y) =(1,4). Find the rate of change for the y coordinate

Answer 1

I can't remember if this is how you do it, but I think its: 2ydy/dt - 8xdx/dt=0

Sub in the coordinates as x and y and dx/dt as a rate of -2 units per second and solve for dy/dt