(k^2)x^2 -(k+2)x+(1/4)=0有实数根,则(1)若k^2=0即k=0,方程即-2x=-1/4,有实数解.（2）若k^2≠0即k≠0,(k+2)^2 -4*(1/4)*(k^2)>=0k^2 +4k+4-k^2>=04k+4>=0k>=-1此时 k>=-1且k≠0综上,k范围是k>=-1...