Introduction to Parabolas

1.

Which feature?

Let's think about what each feature of a parabola shows about the function it represents:

Which feature corresponds to when there are no more bacteria in the population?

The $x$-intercept $(4,0)$ shows that at $4$ days, the population size is $0$.

Answer

The $x$-intercept $(4,0)$ corresponds to when there are no more bacteria in the population.

2.

Which feature?

Let's think about what each feature of a parabola shows about the function it represents:

Which feature corresponds to the bird's height above the ground when it jumped?

The $y$-intercept shows that at the moment the bird jumped, it was $12$ meters above the ground.

Answer

The $y$-intercept $(0,12)$ corresponds to the bird's height above the ground when it jumped.

3.

Which feature?

Let's think about what each feature of a parabola shows about the function it represents:

Which feature corresponds to the ball's maximum height?

The vertex shows that $4$ seconds after Cassie hit it, the ball reached a maximum height of $80$ meters above the ground.

Answer

The vertex $(4,80)$ corresponds to the ball's maximum height.

4.

Which feature?

Let's think about what each feature of a parabola shows about the function it represents:

Which feature corresponds to when the ball hit the ground?

The $x$-intercept $(4,0)$ shows that $4$ seconds after Mia kicked it, the ball is 000 meters above the ground.

Answer

The $x$-intercept $(4,0)$ corresponds to when the ball hit the ground.