title: TypeError: unsupported operand type(s) for ** or pow(): 'str' and 'int'
body: <p>I am just experimenting and having fun with Python 2.7 and I'm trying to write a quadratic equation solver. I had it working when the radicand is positive, but when it's negative im getting an error. even after this if else statement. it also doesnt work with big numbers. thanks for the help.</p>
  
  <pre><code>import math
  a = raw_input("a = ")
  b = raw_input("b = ")
  c = raw_input("c = ")
  float(a)
  float(b)
  float(c)
  radicand = ((b**2)-4*a*c)
  if radicand &gt;= 0:
      print(((0-b) + math.sqrt((b**2)-4*a*c))/(2*a))
      print(((0-b) - math.sqrt((b**2)-4*a*c))/(2*a))
  else:
      print "Imaginary Radical"
  </code></pre>
  
  <p>when i replace (b**2)-4*a*c with radicand i get an invalid syntax error and print is highlighted in red. 
  the error message says 
  TypeError: unsupported operand type(s) for ** or pow(): 'str' and 'int'<br>
  thanks again for any insight you can provide...</p>