Yes,

from there you find the range of x for which

In the case of quadratics, you can alternatively find the axis of symmetry.

The co-efficient of is positive, so the graph is U-shaped.

Hence the slope of the tangent is at or after the minimum,

which occurs halfway between the roots or at the roots in the case of a double root.

Double root at x=3, so the tangent has a positive slope after x=3.