Question

if x= 3 is one root of the quadrati
equation x² -2Kx-6=0, then find the value of k​

Answer 1

Answer:

x=-(b+-√b²-4ac)/2a

3=-2k+-✓4k²+24/2

6=-2k+-√4k²+24

6+2k=√4k²+24

36+4k²+24k=4k²+24

24k=24-36

24k=24-36

k=-12/24

k= -1/2

Answer 2

Answer:

• k = 1/2

Given:

• If x = 3 is one root of the Qudratic equation x² - 2kx - 6 = 0

To find:

• Value of k

Solution:

↝ x² - 2kx - 6 = 0

↝ p (x) = x² - 2kx - 6

↝ x = 3 is a root of p(x)

↝ p(3) = (3)² - 2k(3) - 6

↝ 0 = 9 - 6k - 6

↝ 0 = 3 - 6k

↝ -3 = - 6k

↝ -3/-6 = k

↝ 1/2 = k

↝ k = 1/2

Hence, value of k is 1/2

Explanation more:

• x² - 2k -6 is Qudratic Equation
• A Qudratic equation is nothing but an equation that can be written in standard form
• Qudratic equation formula is ax² + bx + c = 0
• where a , b, and c are real roots and is a is not equal to zero
• Example: 5x² + 4x + 2 = 0 this is Qudratic Equation this is correct in equation ( ax² + bx + c = 0 ) where a = 5x² , b = 4x , c = 2