From Förberedande kurs i matematik 1

The curve \displaystyle y=x^{2} is a parabola with a minimum at the origin according to the figure below on the left and, compared with that curve, \displaystyle y=x^{2}+1 is the same curve but with the number \displaystyle 1 added to the \displaystyle y -coordinate of each point, i.e. the parabola is shifted one unit up in the \displaystyle y -direction.