Adam dropped a rubber ball from a window 40 ft above the sidewalk the ball always bounces half of the height that it drops how far will the ball have travled by the time it hits the sidewalk the 4th time

The ball will reach a height of 5 ft by the 4th time.

Step-by-step explanation:

The initial height of the ball is 40 ft, when it bounces from the floor once the height will be 20 ft, the second time it'll be 10 ft, and so on. The sequence that can represent the maximum height of the ball after each bounce is:

{40, 20, 10,...}

This kind of sequence is called a geometric progression, in this kind of progression the next number is related to the one before it by the product of a constant called ratio, in this case 1/2. To calculate a specific position in this sequence we only need the ratio and the first number, using the formula below:

a_n = a*r^(n-1)

Where n is the position we want to know, a is the first number and r is the ratio. In this case we have:

a_4 = 40*(1/2)^(4-1) = 40*(1/2)^3 = 40/8 = 5

The ball will reach a height of 5 ft by the 4th time.

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

d. all of the above

step-by-step explanation: