Question

If the equation x? - kx + 4 = 0 has equal roots, then the positive k value is

A) k=1
B) k=-1
C) k=2
D) k= -4​

Answer 1

Answer:

k=-4 (D)

Step-by-step explanation:

x²-kx+4=0

a=1 ,b= -k ,c=4

it has equal roots

∆=0

b²-4ac=0

(-k)²-4(1)(4)=0

k²-16=0

k²=16

k=√16

k=±4

k= 4 or -4