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Thread: i think its a algebra or rhyth sorry i am bad at this please look appreciate help

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    i think its a algebra or rhyth sorry i am bad at this please look appreciate help

    (4) N = S(L) + I(t) + R(t), typical R(0) will be 0, and I will be I(0) << N, Ssmall o ~~ not this but 2 of em them on top of eachother and finish with N

    i dont no how to write the numbers correct, i appreciate any kind of assistance.

    now pic is in danish but if it helps more to see what i try to find answer to: https://s7.postimg.org/hch0gsy4r/image1.jpg

    i appreciate if any can explain me this form

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    Elite Member mmm4444bot's Avatar
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    Quote Originally Posted by Deniz View Post
    (4) N = S(L) + I(t) + R(t) That ought to be S(t)

    i appreciate if any can explain me this form
    S(t) represents the output of a function (i.e., the result from using a formula). This notation is generally taught after beginning algebra.

    From what I can tell, t represents elapsed time since an epidemic started. S(t) represents the number of uninfected (susceptible) people in a population.

    For example, if 3,500,000 people were susceptible 20 weeks after the epidemic started, then we could write:

    S(20) = 3 500 000

    where t is measured in weeks.

    I(t) represents the number of infected people, at time t.

    R(t) represents the number of people who have died, at time t.

    N represents the total population. It is a constant.

    N = S(t) + I(t) + R(t)

    The symbol R0 is read as "R sub zero", and it represents the initial value of R (i.e., the number of people who have died at the beginning of the epidemic). In other words, R0 is R(0).

    The equation R0 = 0 simply says that no people have died, yet, at the very beginning (when t = 0).

    The inequality I0 << N says that the initial value of I(t) is very small compared to the total population. In other words, relatively few people in the population were infected, at the beginning.

    S0 ≈ N says that the initial number of uninfected people was approximately the same as N (the total population).

    The rest of the image deals with how fast S, I, and R are changing over time. dS/dt represents such a rate. This is a calculus topic, and equations that contain these rates are called differential equations (studied after calculus).
    "English is the most ambiguous language in the world." ~ Yours Truly, 1969

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    Elite Member stapel's Avatar
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    Cool

    Quote Originally Posted by mmm4444bot View Post
    ...This notation is generally taught after beginning algebra....

    This is a calculus topic, and equations that contain these rates are called differential equations (studied after calculus).
    Thread moved from "Pre-Algebra" to "Differential Equations".

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