Question

9) James started walking away from his house. He started 3 ft away from his front door. He then walked another unknown distance North or South. If North is represented positively and South is represented negatively, which function best represents how far James is away from his house?
A)
f(x) = |x| + 3
B)
f(x) = |x - 3|
C)
f(x) = x(-x) + 3
D)
f(x) = 3x - (x - 3)

Answer 1

do you know how the absolute value function works?

Answer 2

yep
somewhat

Answer 3

okay. one sec.

Answer 4

kk

Answer 5

if he goes north x number of feet, how would you represent his total distance (including the initial 3 feet)?

Answer 6

tbh i literally have no idea

Answer 7

okay, okay.

Answer 8

:/

Answer 9

x is used to represent ANY distance walked. it could be 1 foot, or 120 feet.

Answer 10

if he walks north x number of feet after his initial 3 feet, you would represent that as '3 + x'.

Answer 11

then you can plug in any value for x. whether x = 1 or x = 120.

Answer 12

still with me?

Answer 13

yepp

Answer 14

so north is in the positive direction, south the negative. we aren't interested in the negative value, just the absolute distance walked. this is where the absolute value function comes in.

Answer 15

suppose he walks 20 feet south. then since he is walking in a negative direction, he has still walked 20 feet, right?

Answer 16

yeahh

Answer 17

so we use |x| to show that no matter which direction, we are only interested in the positive value of that distance.

Answer 18

oh alright alright!!

Answer 19

so, what's the answer?

Answer 20

a...

Answer 21

nice work.

Answer 22

\thankss :))))

Answer 23

sure, you are welcome. good luck.