Question

if the roots of quadratic equation x^2+6x+k=0 are equal then the valye of k is​

Answer 1

EXPLANATION.

Quadratic equation.

⇒ x² + 6x + k = 0.

As we know that,

D = Discriminant Or b² - 4ac.

For real and equal roots : D = 0.

⇒ (6)² - 4(1)(k) = 0.

⇒ 36 - 4k = 0.

⇒ 36 = 4k.

⇒ 4k = 36.

⇒ k = 9.

                                                                                                                     

MORE INFORMATION.

Nature of the roots of the quadratic expression.

(1) = Real and unequal, if b² - 4ac > 0.

(2) = Rational and different, if b² - 4ac is a perfect square.

(3) = Real and equal, if b² - 4ac = 0.

(4) = If D < 0 Roots are imaginary and unequal Or complex conjugate.