Which of the following equations is of a parabola with a vertex at (3, 0)? Oy=x^2+3
o y=x^2-3
Oy= (x+3)^ 2
y=(x-3)^ 2

D. y = (x - 3)²

Step-by-step explanation:

The parabola formula in vertex form is:

y = a(x - h)² + k

where the vertex is located at (h, k). Replacing with vertex (3, 0) we get:

y = a(x - 3)² + 0

y = a(x - 3)²

In all possible options the leading coefficient a is equal to one. Therefore:

y = (x - 3)²

- "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."