Question

find the value of k so which the quadratic equation x square + 2√2 kx+ 18=0has equal roots

Answer 1

Answer:

k = ±3

Step-by-step explanation:

For the quadratic equation ax² + bx + c = 0 to have equal roots b² - 4ac should be equal to 0.

Now for equation x²+2√2kx + 18 = 0

a = 1, b = 2√2k ,  c= 18

b² - 4ac = 0

=> (2√2k)² - 4*1*18 = 0

=> 8k² = 72

=> k² = 9

=> k = ±3