SET WINDOW -4, 4, -4, 4  
DRAW axes  
SET POINT STYLE 7
SET COLOR 7

LET stp = 0.0001

FOR x = 0 TO SQR(6) STEP stp
   LET y=SQR(x)+SQR(6-x*x)
   PLOT POINTS: x, y
   PLOT POINTS:-x, y
    
   LET y=SQR(x)-SQR(6-x*x)
   PLOT POINTS: x, y
   PLOT POINTS:-x, y
NEXT x 

END