273. In what sense can it be said that the parabola $y=a x^{2}(a>0)$ is a flattened or elongated parabola $y=x^{2}$? What does the parabola turn into when $a$ decreases without bound?
273. The parabola $y=a x^{2}$ is obtained from the parabola $y=x^{2}$ by multiplying all ordinates $y$ by the same number $a$; if $a<1$, the parabola is compressed, and if $a>1$, it is elongated. When $a$ approaches zero, the parabola approaches the x-axis indefinitely.