Question

3x² + kx + 1 = 0 equation is the majority of the summary of the equation but how much is the value of the mark opposite?​

Answer 1

Answer:

The given quadratic equation is 3x

2

−2kx+12=0

On comparing it with the general quadratic equation ax

2

+bx+c=0, we obtain

a=3,b=−2k and c=12

Discriminant,

′

D

′

of the given quadratic equation is given by

D=b

2

−4ac

=(−2k)

2

−4×3×12

=4k

2

−144

For equal roots of the given quadratic equations, Discriminant will be equal to 0.

i.e., D=0

⇒4k

2

−144=0

⇒4(k

2

−36)=0

⇒k

2

=36

⇒k=±6

Therefore, the values of k for which the quadratic equation 3x

2

−2kx+12=0 will have equal roots are 6 and −6.