Question

if x is equal to 3 is 1 root of the quadratic equation X square - 2 x minus 6 is equal to zero then find the value of k

Answer 1

Solution :-

There is a mistake in this question. The quadratic equation should be x² - 2kx - 6 = 0 

I had solved same question yesterday.


Given that x = 3 is one root of the quadratic equation x² - 2kx - 6 = 0

Substituting x = 3 in the above equation.

⇒ (3)² - (2*k*3) - 6 = 0

⇒ 9 - 6k - 6 = 0

⇒ - 6k = 6 - 9

⇒ - 6k = - 3

⇒ 6k = 3

⇒ k = 3/6

⇒ k = 1/2

So, the value of k is 1/2 

Answer.

Answer 2

Answer:

Given that x = 3 is one root of the quadratic equation x² - 2kx - 6 = 0

Substituting x = 3 in the above equation.

⇒ (3)² - (2*k*3) - 6 = 0

⇒ 9 - 6k - 6 = 0

⇒ - 6k = 6 - 9

⇒ - 6k = - 3

⇒ 6k = 3

⇒ k = 3/6

⇒ k = 1/2

So, the value of k is 1/2