Question

see below

Answer 1

Fiber-optic cables are used widely by broadcast and cable companies. When light passes through a fiber-optic cable, its intensity decreases with the increase in the length of the cable. If 1000 lumens of light enters the cable, the intensity of light decreases by 1.2% per meter of the cable.

Part A: Can this situation be represented by an exponential function? Justify your answer. (2 points)

Part B: Write a function f(x) to represent the intensity of light, in lumens, when it has passed through x meters of the cable. (4 points)

Part C: Some scientists are trying to make a cable for which the intensity of light would decrease by 8 lumens per unit length of the cable. Can this situation be represented by an exponential function? Justify your answer and write the appropriate function to represent this situation if 1000 lumens of light enter the cable. (4 points)

Answer 2

@texaschic101

Answer 3

x is the distance in metres, and it decreases by 1.2% each time, then after each metre, 98.8% remains. Convert 98.8% to a decimal, 0.988.

1000 is the initial, so

1000*(0.988)^x

Answer 4

C: if 8 lumens are lost every meter, then it's just 8 subtracted every meter.

1000 - 8x

Answer 5

Hope I at least helped a little /_^ let me know if I didn't and I can see what more I can do

Answer 6

what about part a? :)

Answer 7

Ahh now I know where I have seen this, here you go :) http://openstudy.com/study#/updates/52801f82e4b07e6b1911bae7

Answer 8

what about part a????

Answer 9

f(x)=1000−1000(0.012)x

Answer 10

Yes, f(x)=1000−1000(0.012)x