Given \( G_1 \) and \( G_2 \) are the slopes of the approach and departure grades of a vertical curve, respectively.
Given \( |G_1| < |G_2| \) and \( |G_1| \neq |G_2| \neq 0 \), Statement 1: \( +G_1 \) followed by \( +G_2 \) results in a sag vertical curve.
Statement 2: \( -G_1 \) followed by \( -G_2 \) results in a sag vertical curve.
Statement 3: \( +G_1 \) followed by \( -G_2 \) results in a crest vertical curve.
Which option amongst the following is true?