Height .

Lana is throwing a discus at a school competitoin. The height of the discus
can be modeled by the equation y=−16x
2
+32x+4, where y represents the
height in feet of the discus in seconds.
Determine the number of seconds for the discus to reach the maximum height.

Step-by-step explanation:

Given the height of the discus can be modeled by the equation y=−16x ^2 +32x+4, where y represents the  height in feet of the discus in seconds, the velocity of the discus at its maximum height is zero.

Velocity v = dy/dx = 0

dy/dx = -32x + 32

0 = -32x + 32

32x = 32

x = 1 secs

Hence it will take the discus 1 secs to reach its maximum height

my guess is

step-by-step explanation:

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true