Which of the following statements is correct for the equation \(x^2+6x+9=0\)?

Correct answer: The discriminant \(D=0\) and the roots are equal

For the given quadratic equation, \(a=1\), \(b=6\), and \(c=9\). Thus, the discriminant is \(D=b^2-4ac=6^2-4(1)(9)=36-36=0\). When \(D=0\), the two roots are real and equal; here, both roots are \(x=-3\). Therefore, option A is correct. Exam tip: \(D=0\) indicates equal roots, \(D>0\) indicates distinct real roots, and \(D<0\) indicates no real roots.