Find the curvature and radius of curvature.

This question involves encapsulation.

y = 3x - 2 given x = a

r (t) = < t, y, 0 >

r (t) = < t, 3t - 2, 0 >

r (t) = (t)i + (3t - 2) j

r'(t) = i + 3 j

||r'(t)|| = root {10}

T(t) = (i + 3 j)/[root {10}]

I am stuck here.