What is the focus and directrix of a vertical parabola

The video tutorial covers the basics of parabolas, focusing on the vertex form and introducing the concepts of focus and directrix. It explains how to calculate these elements and derive the formula for vertical parabolas, emphasizing the role of the parameter P in determining the parabola's direction. The tutorial also discusses the implications of P and A values on the parabola's orientation.

What is the role of the focus in a parabola?

• It determines the width of the parabola.

• It is the highest point of the parabola.

• It is a point from which distances to the directrix are measured.

• It is the midpoint of the parabola.

How is the vertex of a parabola represented in vertex form?

• (P, Q)

• (A, B)

• (X, Y)

• (H, K)

What is the formula for the focus of a vertical parabola?

• (H + P, K)

• (H, K + P)

• (H - P, K)

• (H, K - P)

In the equation of a vertical parabola, what does a positive P indicate?

• The parabola opens to the left.

• The parabola opens downwards.

• The parabola opens upwards.

• The parabola opens to the right.

Why must P not be equal to zero in the parabola's equation?

• Because it would make the vertex undefined.

• Because it would make the parabola a straight line.

• Because it would eliminate the focus.

• Because it would make the parabola open sideways.

What happens when the value of A in the parabola's equation is zero?

• The parabola becomes a line.

• The parabola becomes a point.

• The parabola becomes a hyperbola.

• The parabola becomes a circle.

How does the sign of A affect the direction in which a parabola opens?

• Positive A opens upwards, negative A opens downwards.

• Positive A opens downwards, negative A opens upwards.

• Positive A opens to the right, negative A opens to the left.

• Positive A opens to the left, negative A opens to the right.