MAT1375 D557 Sirelson Spring2019

You must be logged in to reply to this topic.

  • Author
    Posts
  • #53459

    Victor Sirelson
    Participant

    Class Discussion on Exponential models.

    Find an example of an exponential model and post it in this discussion.

    #53460

    Sora
    Participant

    ?

    #53462

    Mona Alzandani
    Participant

    f(x) = 350e^0.0733t

    A(t) is the number of bacteria
    t represents time in minutes

    Question:
    How long will it take for the number of bacteria to double?

    #53463

    Victor Sirelson
    Participant

    SO, how do we think about this?

    #53465

    Johnny Lai Pan
    Participant

    I think this is a great idea to help one another on a open discussion space like openlab.

    #53468

    Johnny Lai Pan
    Participant

    Would someone like to help me out on this problem? Having a hard time.
    Studies show that the maximum half-life of Buprenorphine is 3 days.
    Use the following to construct a function that will model the maximum amount of Buprenorphine left in the body after an initial dose of 10 mg.
    Q(t)=Pe^rt

    Where Q(t) describes the amount of Buprenorphine left in the body after t hours following an initial dose of P mg.

    Q(t)=

    How long (in hours) will it take for the amount of Buprenorphine left in the body to reach 4 mg?

    #53487

    Victor Sirelson
    Participant

    So no one has a suggestion for Johnny?

    If the half-life is 3 days, then after 3 days the initial dose of 10 mg is reduced to half of 10, which is 5.

    Perhaps you can set up the model as 5 = ………..

    #53488

    Abigail
    Participant

    Abigail Perez

    The population of Henderson City was 3,381,000 in 1994, and is growing at an annual rate of 1.8%. If this growth rate continues, what will the approximate population of Henderson City be in the year 2000?

    A=P(1+R)^t

    #53491

    Mona Alzandani
    Participant

    Equation:
    A(6) = 3381000(1 + 0.018)^6

    R = rate if growth
    P = initial population
    t = difference number of 1994 and 2000

    Solution:
    A(6) = 3381000(1 + 0.018)^6
    = 3381000(1.018)^6
    = 3381000(1.112978226)
    = 3762979.382
    You can try and enter it into webwork the way it is shown above or you could simply convert it to billions like so: 3,762,979,382

    #53498

    Mona Alzandani
    Participant

    Part 1:
    Q(t) = 10(.5^(t/72))

    Part 2:
    4 = 10(.5^(t/72))
    (Divide 10 from both sides)
    4/10 = .5^t/72
    (Multiply by (In) to bring the exponent down)
    In(4/10) = t/72 In(.5)
    (Divide In(.5) on both sides)
    In(4/10)/In(.5) = t/72
    (Multiply both sides by 72)
    (In(4/10)/In(.5)) x 72 = t
    95.178 = t

    #53537

    Johnny Lai Pan
    Participant

    A little stuck on the this problem.

    Given that α is in quadrant 2 and sin(α)=5/8,
    and also given that β is in quadrant 1 and tan(β)=2/9,
    give an exact answer for the following:

    sin(α+β)=
    cos(α+β)=
    tan(α+β)=

    #53542

    Victor Sirelson
    Participant

    I found it helpful to draw a right triangle in the given quadrant, and to label it according to the given values. So sin(α) = 5/8 in Q2 would give a triangle with the x-side to the right (minus) and the y-side up. Then the y-side = 5 and the hypotenuse = 8 and I can calculate the x-side.

    Using this I can get the values for all of the trig functions for α. I do the same for β

    Then I write down the expression for the sin( α+β) = and I can now use the values I have already determined from my two triangles.

    #53549

    Johnny Lai Pan
    Participant

    Thank you Prof. I understood what you were explaining during class and here.

    #53588

    dlovitt
    Participant

    Let’s go back to our problem and list all solutions for sin(x)=1/2
    sin⁡(x)=1/2 in [0,2π)

    x=(pi/6), ((5pi)/6)

    Now, list all solutions for sin(x)=1/2
    sin⁡(x)=1/ in (−2π,0]

    I understand how I got the first one but for some reason I am not understanding the second part.

    #53593

    Faisal
    Participant

    basically you do the same thing but instead of adding 2pi, do minus 2pi

Viewing 15 posts - 1 through 15 (of 15 total)

You must be logged in to reply to this topic.