Solved Calculating radial coordinate from position based off vertical yaw?

I'm trying to keep track of a position 1 block behind me from the direction I look, but I've no idea how to do this smoothly!

Code:

                    
Location Target = player.getLocation();
double yaw = Target.getYaw();
double x = 0, z = 0;

// calculate  X, Z value behind player based on vertical yaw, direction player is facing?

Target.add(x, 0.0D, z);
entity.teleport(Target);

I'm sure this has to be a common function in many games where you calculate a radial position/coord around a player based on their face direction, can anyone point me to what this calculation would be called? Or.. how to do this?

EDIT:

Code:

Location Target = p.getLocation();
double yaw = Target.getYaw() - 85;
                     
double x = 0, z = 0;
                     
x=Math.cos(yaw*0.02F)*0.2;
z=Math.sin(yaw*0.02F)*0.2;
                     
Target.add(x, 0.0D, z);
entity.teleport(Target);

This is doing what I needed!
It's keeping an entity following just behind me and stays behind me no matter where I turn.