geometry - A reverse of Haversine formula for MySQL?

In my DB i store a center point, along with a radius (in meters).

I'm looking to pass in a lat/lng, and then have the mysql values i've stored create a circle to tell me if my point i passed in is within that circle. Is there something that would allow me to do this, similar to the haversine forumla (which would assume that my point was already in the db).

Haversine Formula:
( 3959 * acos( cos( radians(40) ) * cos( radians( lat ) ) * cos( radians( long ) - radians(-110) ) + sin( radians(40) ) * sin( radians( long ) ) )

db:

circleLatCenter, circleLngCenter, Radius

passing in>
select id from foo where lat,lng in (make circle function: circleLat, circleLng, radius)

Answer

MySQL has a whole host of spatial data functions:

Spatial Extensions to MySQL

I think the section on measuring the relationships between geometries is what you're after:

Relationships Between Geometries