Question

hhelp plz ill post the document.. its urgent please.
1. find a function of the form y= c+asin[w(t-b)] for hare population
2. find a function of the form y= c+asin[w(t-b)] for lynx population
3. add the two function together to get a new function and find the average, amplitude, period and a sine phase shift.

Answer 1

@ hero help plz satelite not online :d

Answer 2

i know that for the hares population, the amplitude is 2000, the period is pie over 125 and i dont see any phase shift

Answer 3

The amplitude is half the measure from peak to peak.
(3500 - 500) / 2 = 1500
a = 1500

Answer 4

isnt amplitude the max?

Answer 5

amplitude is the max oscillation about the mean. because of c, the curve is shifted up and so the max will be bigger than the amplitude.

Answer 6

The distance between the lowest points is: 210 - 90 = 120 which is the period. So the cycle repeats itself every 120 weeks.
period = 2pi/w = 120. So w = 2pi/120 = pi/60.

Answer 7

y = c + a * sin[w(t-b)]
y = c + 1500 * sin[pi/60(t - b)]
when t = 0, y = 2000
2000 = c + 1500 * sin[-pi/60 * b]

Answer 8

when t = 90, y = 500
500 = c + 1500 * sin[-pi/60(90 - b)]
2 unknowns, 2 equations. solve for c and b

Answer 9

im still confused sorry

Answer 10

subtract second equation from first. that will eliminate c. you can solve for b.

Answer 11

k

Answer 12

I am beginning to think that c is simply 2000 because it lifts the sine wave which has a zero y intercept by 2000 to give it a y-intercept of 2000.

So c may simply be 2000.

Answer 13

If we put c = 2000 in
2000 = c + 1500 * sin[-pi/60 * b] we get
2000 = 2000 + 1500 * sin[-pi/60 * b]
1500 * sin[-pi/60 * b] = 0
sin[-pi/60 * b] = 0
-pi/60 * b = 0 (or pi)
b = 0 or ...

Answer 14

sorry but i give up ill talk to my prof tomorrow cuz this is too hard

Answer 15

ok. do you have the answer?

Answer 16

yeh

Answer 17

I think y = 2000 + 1500 * sin(pi/60 * t) for the hare population.

Answer 18

what is the answer?

Answer 19

I put a few select values of t in the above equation and it gives the y-values correctly.
You don't want to give the answer?

Answer 20

im trying really but i just cant get it

Answer 21

No I meant answer form the back of the text book or multiple choice answers.