Question

help

Answer 1

@jim_thompson5910

Answer 2

what do you have so far for this?

Answer 3

nothing ;( i tried looking at it but i can't figure anything to write

Answer 4

what is the initial amount of lumens we have?

Answer 5

ie what is the starting amount of light intensity?

Answer 6

1200

Answer 7

Correct. Now let's say we travel 1 meter down the cable. What is the intensity now?

Answer 8

still 1200 ?

Answer 9

the light decreases 2.5% per meter of cable

Answer 10

if you take 1200 and decrease it by 2.5%, you get ???

Answer 11

uhhhh 1200*2.5% correct

Answer 12

close

Answer 13

you must do 100-2.5 = 97.5

so you're really multiplying 100 by 97.5%, ie 100*0.975

Answer 14

oops not 100, 1200

Answer 15

1200*0.975

Answer 16

if we want to know the intensity when it goes 2 meters, then we multiply by 0.975 again (to reduce it by 2.5%)

1200*0.975*0.975 = 1200(0.975)^2

do you see a pattern emerging?

Answer 17

yes somewhat

Answer 18

if we want to know the intensity when it goes 3 meters, then we multiply by 0.975 a third time

1200*0.975*0.975*0.975 = 1200(0.975)^3

and so on

Answer 19

how about 4 meters?

Answer 20

uh maybe

Answer 21

what do we do if we want to find the intensity for 4 meters?

Answer 22

the other equation

Answer 23

what do you mean?

Answer 24

1200*0.975*0.975*0.975*0.975 = 1200(0.975)^4

Answer 25

@jim_thompson5910

Answer 26

correct

Answer 27

so in general, for x meters, we have

1200*0.975*0.975*0.975*0.975 *0.975*0.975*...*0.975

x copies of 0.975 multiplied

Answer 28

therefore, in general, the expression is 1200*(0.975)^x

Answer 29

agreed or no?