Question

The discriminant of x²-3x + k=0 is 1 then the value of k =___
A -4
B 4
c -2 d 2​

Answer 1

EXPLANATION.

Discriminant of the equation,

F(x) = x² - 3x + k is 1.

As we know that,

Discriminant = D = b² - 4ac.

⇒ (-3)² - 4(1)(k) = 1.

⇒ 9 - 4k = 1.

⇒ -4k = 1 - 9.

⇒ -4k = -8.

⇒ k = 8/4.

⇒ k = 2.

Option [D] is correct answer.

                                                                                                                     

MORE INFORMATION.

Nature of the factors of the quadratic expression.

(1) = Real and different, 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.

Answer 2

Answer:

Given :-

The discriminant of x²-3x + k=0 is 1

To Find :-

Value of k

Solution :-

As we are knowing that

D = b² - 4ac

• D = ?
• b = -3
• a = 1
• c = k

1 = (-3)² - 4(1)(k)

1 = 9 - 4(1)(k)

1 = 9 - 4k

1 - 9 = -4k

-8 = -4k

-8/-4 = k

8/4 = k

2 = k

Value of k is 2