Answer:
d = 2* sqrt(a^2 + b^2)
Explanation:
Interesting question. You should begin by noting that 0 is not the answer although it looks like it should be.
P = (a,b)
Q= (-a,-b)
x1 = a
x2 = - a
y1 = b
y2 = - b
d = sqrt( (x2 - x1)^2 + (y2 - y1)^2 )
d = sqrt( (-a - a)^2 + (-b - b)^2 )
d = sqrt ( -2a)^2 + - (2b)^2 )
d = sqrt(4a^2 + 4b^3)
d = 2* sqrt(a^2 + b^2)