To find the range in the distance x, you should solve this compound inequality


    1600 <=  <= 3600.


    +--------------------------------------+
    |   It is opposite to your intention,  |
    |   as you presented it in your post.  |
    +--------------------------------------+


Left side of this inequality,  1600 <= ,  gives you

     <= ,   <= ,  x <= ,  x <=  = 0.75  meters.



Right side of this inequality,   <= 3600,  gives you

     >= ,   >= ,  x >= ,  x >=  = 0.5  meters.



Thus the  ANSWER  for the range of  x  is  0.5 meters <= x <= 0.75 meters.