An athletics squad trains on a long straight track with dots marked at 10m intervals. The coach sets out cones on some of the dots for the squad's sprint training drills. She wants the squad to be able to run any distance which is a multiple of 10m, up to some maximum distance which depends on the number of cones. Explain why it is not possible to place four cones A, B, C, D, in a line so that each multiple of 10m up to 70m can be run between two of the cones.

There are 6 ways to run 10 m between two cones of the four cones giving a maximum available distance to run as 60 meters

Step-by-step explanation:

The parameters given are

Distance between two cones = 10 m

Number of cones = 4

Therefore, number of ways to choose two 10 m distances (distance between two cones) from the four cones = = 6

Hence there are only six 10 m distances to run between two cones which gives a maximum distance available to run as 60 m.

let's cover over the formula of the vertex:

y = a(x – h)^2 + k

in this formula, (h,k) are the vertex, always remember that the positive or negative value of the vertex is based on the sign it has.

for example, if the vertex is -3,-6 then both the x and y value would have the positive sign attached to it and if it were a positive x and y value, then a negative sign would be attached to it.

with that being said, for our problem the x value is a positive one so we are looking for a number with a negative sign next to it, in this case the first and second choice.

however, for the first answer choice it isn't quite part of the formula so we know that the answer choice correctly displays the x value.

to confirm, we can see if the -1 fits correctly with the second answer choice, and as mentioned above a negative number will have a positive sign attached to it. so, for our problem we can see that -1 has been changed to +1, so we can confirm that the second answer choice is correct.

hence, our final answer is y=(x - 1)^2 + 1