must also increase. Therefore, we must be moving up the curve from bottom to top as tincreases as that is the only direction that will always give an increasing yas tincreases. Note that the xderivative isn’t as useful for this analysis as it will be both positive and negative and hence xwill be both increasing and decreasing depending on the value of t. That doesn’t help with direction much as following the curve in either direction will exhibit both increasing and decreasing xIn some cases, only one of the equations, such as this example, will give the direction while in other cases either one could be used. It is also possible that, in some cases, both derivatives would be needed to determine direction. It will always be dependent on the individual set of parametric equations. The second problem with eliminating the parameter is best illustrated in an example as we’ll be running into this problem in the remaining examples.