Eliminating a Parameter In Exercises $39-42,$ eliminate the parameter and obtain the standard form of the rectangular equation.

$39.$ Line through $(x_1,y_1)$ and $(x_2,y_2)$ :

$x=x_{1}r(x_2-x_1),y=y_{1}r(y_2-y_1)$

Circle: $x=hrcos,y=krsin$

Ellipse: $x=h$ acos$,y=k$ bsin$$

Hyperbola: $x=h$ asec$,y=k$ btan$$