Which intersection forms a parabola?

Answer

A plane intersects only one nappe of a double-napped cone, and the plane is not parallel to the generating line of the cone.

Step-by-step explanation:

Parabola is a symmetrical open plane bend framed by the crossing point of a cone with a plane parallel to its side. The way of a shot affected by gravity in a perfect world takes after a bend of this shape.

7

step-by-step explanation:

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."