Question

A man is walking down the beach away from lighthouse A and toward point C. When he is x kilometers away from lighthouse A and has not yet reached point C, write the illumination he receives as a function of x in simplest form.

Answer 1

Lighthouse A, located on an ocean shore, uses a 10-kW light. Lighthouse B uses a 20-kW light and is located 8 km out to sea from a point 6 km down the beach from Lighthouse A.

Answer 2

you can measure the distance from point B using pythagorean thm
d=82+(6−x)2−−−−−−−−−−−√=x2−12x+100−−−−−−−−−−−−√

is illumination measured by watts*distance ?
if so then function is
l=10x+20x2−12x+100−−−−−−−−−−−−√

Answer 3

:) have to go - did this help?

Answer 4

Thanks. The formula is 10/x^2+20/sqrt(x^2-12x+100)

Answer 5

what should i do from now?

Answer 6

was hoping I could paste the doc in Word to you -
shoot I have to go - :( I am sorry I couldn't help you more )

Answer 7

let me see if I can try again

Answer 8

I can forward this to a friend of mine in FB later on if noone helps you (he is a math teacher in California) and he can respond - his FB is: Just Plane Math on Facebook.

Answer 9

lol I am a girl ;)

Answer 10

https://www.facebook.com/pages/Just-Plane-Math/255647914493669
That is his page - and he is usually able to help when others can't :)

Answer 11

:) thanks

Answer 12

K, he is responding - I will try to copy this to you-