Its 
  
    
      
        3
      
    
    {\displaystyle 3}
   x 
  
    
      
        3
      
    
    {\displaystyle 3}
   array of squares has a magic constant 
  
    
      
        M
      
    
    {\displaystyle M}
   of 
  
    
      
        15
      
    
    {\displaystyle 15}
  , where the sums of its rows, columns, and diagonals are all equal to fifteen. 5 is also the value of the central cell the only non-trivial order-3 normal magic hexagon that is made of nineteen cells.Polynomial equations of degree 4 and below can be solved with radicals, while quintic equations of degree 5, and higher, cannot generally be so solved. This is the Abel–Ruffini theorem.
Corrective therapy
Since vasospasms can be caused by atherosclerosis and contribute to the severity of ischemia there are some surgical options which can restore circulation to these ischemic areas. Regarding coronary vasospasm, one surgical intervention, referred to as percutaneous coronary intervention or angioplasty, involves placing a stent at the site of stenosis in an artery and inflating the stent using a balloon catheter. Another surgical intervention is coronary artery bypass. See also
Coronary artery vasospasm
Raynauds phenomenon, a vasospastic disorder
Reversible cerebral vasoconstriction syndrome

References


== External links ==