A continuación se muestran seis gráficos. Hacer clic en las pestañas para verlos. Marcar la casilla correspondiente a cada gráfico que represente una función.

A graph represents a function if and only if every vertical line drawn through the graph intersects the graph at most once. If a vertical line intersects the graph at two or more points, then it is not a function.

"Gráfico 3" shows a parabola that opens downwards.
Imagine drawing vertical lines across this graph. For any given x-value, a vertical line will intersect the parabola at exactly one point. For example, at $x=0$, the graph intersects at $y=0$. At $x=1$ or $x=-1$, the graph intersects at approximately $y=-1$. At $x=2$ or $x=-2$, the graph intersects at approximately $y=-4$.

Since every vertical line intersects the graph of "Gráfico 3" at exactly one point, it satisfies the condition for being a function.

Therefore, "Gráfico 3" represents a function.

Gráfico 3 represents a function.