$\"\"$

The center of the circle equation is $\"\"$ and radius is $\"\"$ .

From problem (40):

The parametric equations for circle equation are $\"\"$ and $\"\"$ .

Substitute $\"\"$ and $\"\"$ in $\"\"$ .

$\"\"$

Substitute $\"\"$ and $\"\"$ in $\"\"$ .

$\"\"$

The parametric equations for circle equation are $\"\"$ and $\"\"$ .

$\"\"$

The parametric equations for circle equation are $\"\"$ and $\"\"$ .