Question

i need help!!!

the table below represents the distance of a car from its destination as a function of time

time (hours) distance
(miles)
0 900
1 850
2 800
3 750

what is the y intercept of a function and what does this tell you about the car?

calculate the average rate of change of the function represented by the table between x=1 to x=3?

what would be the domain of this function if the car traveled the same rate until it reached its destination?

Answer 1

start by finding the y-intercept

Answer 2

if x = time and y = distance, what is the distance when x = 0 ?

Answer 3

900

Answer 4

sorry i had to take my dog out

Answer 5

good, so the y-intercept is (0,900) which means the car starts off at 900 miles away from its destination

Answer 6

for average rate of change, you want to find

(distance when x = 3) - (distance when x = 1)

Answer 7

then divide that by 2

Answer 8

distance equals 750 when time is 3 and the distance equals 850 when the time equals one

Answer 9

good, then we subtract

Answer 10

750 - 850 = -100

Answer 11

then divide by 2, to get -50

Answer 12

okay

Answer 13

the slope is -50 and the y-intercept is 900 so we have the equation

y = -50x + 900

to find the domain, let y = 0 and solve for x

0 = -50x + 900

x = ?

Answer 14

so 0-900?

Answer 15

-900 = -50x

x = ?

Answer 16

okay so -900/-50

Answer 17

right, keep going

Answer 18

-900/-50 = ??

Answer 19

18

Answer 20

right?

Answer 21

right, so the domain is all real numbers from x = 0 to x = 18

you can write this as [0,18]

Answer 22

okay

Answer 23

and that's it

Answer 24

thank you so much