The vertical axis is labeled T(N) (running time). The horizontal axis is labeled N (the problem size). There are four graph lines. A straight line labeled T(N) = N starts at the origin and ascends at a 45-degree angle to the right. A line labeled T(N) = N + 2 is parallel to this line, above it. A straight line labeled T(N) = 1.5 N starts at the origin and ascends at a steeper angle than the other lines. A blue line labeled T(N) = 0.5 N squared starts at the origin and curves upward at an increasingly steep angle.