Description:
------------
Great problem with calculation power two - how easy, have a look 

B^2 = B*B

but not in PHP. Please run a example. If B = 12E4, than B*B is not B^2 !!!

Test script:
---------------
$A=1; $B=6.911824E4; $C=3.95554E8;
    
   // $D = $B^2-4*$A*$C; $sqr=sqrt($D);   echo "discriminant = $D <br>";
    
    $D = $B*$B;    echo "B*B = $D  <br>";
    $D = $B^2;     echo "B^2 = $D  <br>"; # <-- Here is deferent number !!!
    

   // $D = 4*$A*$C; echo "4*A*C = $D <br>";
    

Expected result:
----------------
B*B = 4777331100.6976 
B^2 = 69116                 # <-- Incorrect !


B*B = 4777331100.6976       # good answer

Actual result:
--------------
B^2 = 69116                 # <-- Incorrect !