If a,b,c are non zero real numbers and az2+bz+c+i=0 has purely imaginary roots, then a=

• underroot(b^2-(4a(c+i))).... so for the root to be imaginary the equation inside the root should be negative soooo...
  4a(c+i)>(b^2) therefore a>(b^2)/(c+i).
• 9 years agoHelpfull: Yes(1) No(0)