First thing to do is to find the stationary point of the curve. This is done by differentiating the function and then equating to zero, as the gradient of the stationary point is zero. Setting dy/dx to zero and solving for x, will yield x=-1. Since we are finding the bisector to a stationary point it will be a straight vertical line, so we have all the information we need and hence, the line that bisects the stationary point is x=-1.