A vertical parabolic curve, $135$ meters long has a tangent grades of $-1.7 \space \%$ and $2.3 \%$. Find the sight distance in meters.

Question

I am interested in answering this problem. It goes like this:

A vertical parabolic curve, $135$ meters long has a tangent grades of $-1.7 \space \%$ and $2.3 \%$. Find the sight distance in meters.

My work

I don't know how to answer this.

I am interested in what topic in mathematics does the question belongs and I am curious in how to answer the problem above.

Thanks for helping me out:-)