Thread: Problem Finding a Parametrization for a Circle

Hey guys,
I am having a little difficulty solving a problem. It says: Find a parametrization for the circle having radius 3 and center (3, 4, −5) that lies in a plane parallel to the zx-plane.

Well, I initially just combined the center with the radius to get parametric equations of :
x = 3 + 3cost, y = 4, z = -5 +3sint, but this appears to be wrong. Can anyone tell me what I am doing wrong.

Any help and feedback is greatly appreciated, thanks.

Originally Posted by Beevo

Hey guys,
I am having a little difficulty solving a problem. It says: Find a parametrization for the circle having radius 3 and center (3, 4, −5) that lies in a plane parallel to the zx-plane.

Well, I initially just combined the center with the radius to get parametric equations of :
x = 3 + 3cost, y = 4, z = -5 +3sint, but this appears to be wrong. Can anyone tell me what I am doing wrong.


Any help and feedback is greatly appreciated, thanks.

You have a correct parameterization of a circle. The only thing I can think of is that they asked for it to have a certain orientation. The circle is oriented counter clockwise around the unit vector in the plane

Originally Posted by TheEmptySet

You have a correct parameterization of a circle. The only thing I can think of is that they asked for it to have a certain orientation. The circle is oriented counter clockwise around the unit vector in the plane

If it is oriented counter clockwise around the unit vector, how would it change the parametrization? Would it simply change the signs of my current parametrization?