Functions Vertical Line Test Posted on 11th January 201822nd February 2018 by TimGan The use of the vertical line test determines if a line equation is a function. If the vertical line intersects only 1 point, the line equation is a function. If the vertical line intersects more than 1 point, the line equation is not a function. TimGan Solving integration by the use of partial fractions VJC/2013/Prelim/P1/Q1