Question

Find the value(s) of k for which the quadratic equation x2 + 2√2kx + 18 = 0 has equal
roots​

Answer 1

Answer: k=+ or- 3

Step-by-step explanation:

Answer 2

Answer:

The value of k is 3 and -3.

Step-by-step explanation:

Given : Equation $x^2+2\sqrt2 kx+18=0$

To find : The values of k for which the quadratic equation has equal roots ?

Solution :

The quadratic equation $ax^2 + bx + c = 0$ has equal roots when discriminant zero,

i.e. $b^2 - 4ac = 0$

On comparing,

$a=1,\ b=2\sqrt2 k,\ c=18$

Substitute the values,

$(2\sqrt2 k)^2-4(1)(18)= 0$

$8k^2-72= 0$

$8k^2=72$

$k^2=\frac{72}{8}$

$k^2=9$

$k=\sqrt{9}$

$k=\pm 3$

Therefore, The value of k is 3 and -3.