The potential energy due to the strong interaction, between two quarks or a quarkantiquark pair, goes something like v (r) = −α/r + βr, where α and β are positive constants. is there any point rv where the potential energy goes to zero? is there any point

Given that 
V= x/r + Br.
If V=0 Then -x/r + Br = 0
→ -x + br²/r = 0
→Br² - x = 0
r² = x/B
r² = +₋ √x/B
Force = dv/dr = d/dr [ -x/r +Br]
F = -[ -x/-r² + B]
= [B +x/r²]
a,B are positive.
r² is constant and it can never be negative.
∴ [ B + x/r²] is a positive value.
V = 0 at r = ⁺₋√x/B for the value of r.