To find the offset at the PVT (point of vertical tangency) of a 600-ft long equal-tangent vertical curve connecting an initial grade of 1.2% and a final grade of -1.08%, you can use the following formula:

Where:
L = Length of the curve = 600 ft
E1 = Initial grade = 1.2%
E2 = Final grade = -1.08%
Substituting the given values into the formula, we get:



Therefore, the offset at the PVT of this vertical curve is 3.6 feet