Answer:
In ax
2
+bx+c=0,
Discriminant D =b
−4ac,
D=0, for the roots to be real and equal
In 2x
+px+8=0
Thus, we have a=2,b=p and c=8
Then D =b
−4ac=0
∴p
−4×2×8=0⇒p
−64=0
⇒p=±8.