To have exactly one solution, the quadratic equation y=x^2+bx+5 must have a discriminant of zero. The discriminant is b^2-4ac, where a=1, b=b, and c=5.
Therefore, b^2-4ac = b^2 - 4(1)(5) = b^2 - 20 = 0.
Solving for b, we get:
b^2 = 20
b = ±√20
Since b>0, we have:
b = √20
b ≈ 4.47