Question

If the sum and product of root of the equation3x² + 6x + k = 0 are equal, then k​

Answer 1

Answer:

Given that ;

Quadratic Equation :

3x² + 6x + k = 0

Discriminant ( ∆ ) = b² - 4ac

a = 3 ; b = 6 ; c = k

∆ = ( 6 )² - 4 ( 3 ) ( k )

∆ = 36 - 12k

36 = 12k

k = 36 / 12

k = 3

Hence ;

Value of k ;

K = 3

Answer 2

Let's find the root of the equation first:

3x² + 6x + k = 0

a=3, b=6 and c=k

using formula: -b±√b²-4ac/2a

=-6+√36-12k/6, -6-√36-12k/6

=a+b

according to the question,

a+b=ab

-6+√36-12k/6-6-√36-12k/6=(-6+√36-12k/6)*(-6-√36-12k/6)

-2=k/3

k=-6