The following graph shows a distribution curve given by a function of the form $f(x)=A/(x+2e^{rx})$












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$begingroup$


The following graph shows a distribution curve given by a function of the form $$f(x)=dfrac{A}{x+2e^{rx}}$$



Graph to the question



Determine the equation $f(x)$ of the graph.










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  • $begingroup$
    Do you mean $xe^r$ or $e^{rx}$?
    $endgroup$
    – Shubham Johri
    Dec 17 '18 at 11:40










  • $begingroup$
    Welcome to the website. Please typeset your equations using Mathjax. Also, kindly include how you have tried to approach the problem so that we know you are not just trying to get your homework solved and can offer you focused guidance.
    $endgroup$
    – Shubham Johri
    Dec 17 '18 at 11:42










  • $begingroup$
    Do you mean: $$f(x)=frac{A}{x+2e^{rx}}$$
    $endgroup$
    – projectilemotion
    Dec 17 '18 at 11:52










  • $begingroup$
    yeah @projectilemotion
    $endgroup$
    – KJ26
    Dec 17 '18 at 11:53






  • 1




    $begingroup$
    One easy way to do it is to use two of the points you were given and solve the resulting system. In my opinion, the easiest way is to first use $(0,10)$, then $(1,12)$.
    $endgroup$
    – projectilemotion
    Dec 17 '18 at 11:55


















1












$begingroup$


The following graph shows a distribution curve given by a function of the form $$f(x)=dfrac{A}{x+2e^{rx}}$$



Graph to the question



Determine the equation $f(x)$ of the graph.










share|cite|improve this question











$endgroup$












  • $begingroup$
    Do you mean $xe^r$ or $e^{rx}$?
    $endgroup$
    – Shubham Johri
    Dec 17 '18 at 11:40










  • $begingroup$
    Welcome to the website. Please typeset your equations using Mathjax. Also, kindly include how you have tried to approach the problem so that we know you are not just trying to get your homework solved and can offer you focused guidance.
    $endgroup$
    – Shubham Johri
    Dec 17 '18 at 11:42










  • $begingroup$
    Do you mean: $$f(x)=frac{A}{x+2e^{rx}}$$
    $endgroup$
    – projectilemotion
    Dec 17 '18 at 11:52










  • $begingroup$
    yeah @projectilemotion
    $endgroup$
    – KJ26
    Dec 17 '18 at 11:53






  • 1




    $begingroup$
    One easy way to do it is to use two of the points you were given and solve the resulting system. In my opinion, the easiest way is to first use $(0,10)$, then $(1,12)$.
    $endgroup$
    – projectilemotion
    Dec 17 '18 at 11:55
















1












1








1





$begingroup$


The following graph shows a distribution curve given by a function of the form $$f(x)=dfrac{A}{x+2e^{rx}}$$



Graph to the question



Determine the equation $f(x)$ of the graph.










share|cite|improve this question











$endgroup$




The following graph shows a distribution curve given by a function of the form $$f(x)=dfrac{A}{x+2e^{rx}}$$



Graph to the question



Determine the equation $f(x)$ of the graph.







algebra-precalculus graphing-functions






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share|cite|improve this question













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share|cite|improve this question








edited Dec 17 '18 at 11:54









projectilemotion

11.4k62141




11.4k62141










asked Dec 17 '18 at 11:37









KJ26KJ26

83




83












  • $begingroup$
    Do you mean $xe^r$ or $e^{rx}$?
    $endgroup$
    – Shubham Johri
    Dec 17 '18 at 11:40










  • $begingroup$
    Welcome to the website. Please typeset your equations using Mathjax. Also, kindly include how you have tried to approach the problem so that we know you are not just trying to get your homework solved and can offer you focused guidance.
    $endgroup$
    – Shubham Johri
    Dec 17 '18 at 11:42










  • $begingroup$
    Do you mean: $$f(x)=frac{A}{x+2e^{rx}}$$
    $endgroup$
    – projectilemotion
    Dec 17 '18 at 11:52










  • $begingroup$
    yeah @projectilemotion
    $endgroup$
    – KJ26
    Dec 17 '18 at 11:53






  • 1




    $begingroup$
    One easy way to do it is to use two of the points you were given and solve the resulting system. In my opinion, the easiest way is to first use $(0,10)$, then $(1,12)$.
    $endgroup$
    – projectilemotion
    Dec 17 '18 at 11:55




















  • $begingroup$
    Do you mean $xe^r$ or $e^{rx}$?
    $endgroup$
    – Shubham Johri
    Dec 17 '18 at 11:40










  • $begingroup$
    Welcome to the website. Please typeset your equations using Mathjax. Also, kindly include how you have tried to approach the problem so that we know you are not just trying to get your homework solved and can offer you focused guidance.
    $endgroup$
    – Shubham Johri
    Dec 17 '18 at 11:42










  • $begingroup$
    Do you mean: $$f(x)=frac{A}{x+2e^{rx}}$$
    $endgroup$
    – projectilemotion
    Dec 17 '18 at 11:52










  • $begingroup$
    yeah @projectilemotion
    $endgroup$
    – KJ26
    Dec 17 '18 at 11:53






  • 1




    $begingroup$
    One easy way to do it is to use two of the points you were given and solve the resulting system. In my opinion, the easiest way is to first use $(0,10)$, then $(1,12)$.
    $endgroup$
    – projectilemotion
    Dec 17 '18 at 11:55


















$begingroup$
Do you mean $xe^r$ or $e^{rx}$?
$endgroup$
– Shubham Johri
Dec 17 '18 at 11:40




$begingroup$
Do you mean $xe^r$ or $e^{rx}$?
$endgroup$
– Shubham Johri
Dec 17 '18 at 11:40












$begingroup$
Welcome to the website. Please typeset your equations using Mathjax. Also, kindly include how you have tried to approach the problem so that we know you are not just trying to get your homework solved and can offer you focused guidance.
$endgroup$
– Shubham Johri
Dec 17 '18 at 11:42




$begingroup$
Welcome to the website. Please typeset your equations using Mathjax. Also, kindly include how you have tried to approach the problem so that we know you are not just trying to get your homework solved and can offer you focused guidance.
$endgroup$
– Shubham Johri
Dec 17 '18 at 11:42












$begingroup$
Do you mean: $$f(x)=frac{A}{x+2e^{rx}}$$
$endgroup$
– projectilemotion
Dec 17 '18 at 11:52




$begingroup$
Do you mean: $$f(x)=frac{A}{x+2e^{rx}}$$
$endgroup$
– projectilemotion
Dec 17 '18 at 11:52












$begingroup$
yeah @projectilemotion
$endgroup$
– KJ26
Dec 17 '18 at 11:53




$begingroup$
yeah @projectilemotion
$endgroup$
– KJ26
Dec 17 '18 at 11:53




1




1




$begingroup$
One easy way to do it is to use two of the points you were given and solve the resulting system. In my opinion, the easiest way is to first use $(0,10)$, then $(1,12)$.
$endgroup$
– projectilemotion
Dec 17 '18 at 11:55






$begingroup$
One easy way to do it is to use two of the points you were given and solve the resulting system. In my opinion, the easiest way is to first use $(0,10)$, then $(1,12)$.
$endgroup$
– projectilemotion
Dec 17 '18 at 11:55












1 Answer
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$begingroup$

From the given form $f=frac{A}{1+2e^{rx}}$ and by checking the points on the graph we get
$$begin{aligned}
10&=f(0)=frac{A}{0+2e^{rcdot0}}=frac{A}{2} implies A=20 &&(text{I})\
12&=f(1)=frac{A}{1+2e^{rcdot1}}overset{text{(I)}}{=}frac{20}{1+2e^r} &&text{(II)}\
9&=f(2)=frac{A}{2+2e^{rcdot2}}overset{text{(I)}}{=}frac{10}{1+e^{2r}} &&text{(III)}\
end{aligned}$$

transform (II):
$$
12=frac{20}{1+2e^r} iff 12(1+2e^{r})=20 iff 24e^{r}=8 iff e^r=frac{1}{3} iff r=lnleft(frac{1}{3}right)
$$

So
$A=20$ and $r=ln(frac{1}{3})approx -1.0986$. (III) is not needed for this.






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    $begingroup$

    From the given form $f=frac{A}{1+2e^{rx}}$ and by checking the points on the graph we get
    $$begin{aligned}
    10&=f(0)=frac{A}{0+2e^{rcdot0}}=frac{A}{2} implies A=20 &&(text{I})\
    12&=f(1)=frac{A}{1+2e^{rcdot1}}overset{text{(I)}}{=}frac{20}{1+2e^r} &&text{(II)}\
    9&=f(2)=frac{A}{2+2e^{rcdot2}}overset{text{(I)}}{=}frac{10}{1+e^{2r}} &&text{(III)}\
    end{aligned}$$

    transform (II):
    $$
    12=frac{20}{1+2e^r} iff 12(1+2e^{r})=20 iff 24e^{r}=8 iff e^r=frac{1}{3} iff r=lnleft(frac{1}{3}right)
    $$

    So
    $A=20$ and $r=ln(frac{1}{3})approx -1.0986$. (III) is not needed for this.






    share|cite|improve this answer











    $endgroup$


















      1












      $begingroup$

      From the given form $f=frac{A}{1+2e^{rx}}$ and by checking the points on the graph we get
      $$begin{aligned}
      10&=f(0)=frac{A}{0+2e^{rcdot0}}=frac{A}{2} implies A=20 &&(text{I})\
      12&=f(1)=frac{A}{1+2e^{rcdot1}}overset{text{(I)}}{=}frac{20}{1+2e^r} &&text{(II)}\
      9&=f(2)=frac{A}{2+2e^{rcdot2}}overset{text{(I)}}{=}frac{10}{1+e^{2r}} &&text{(III)}\
      end{aligned}$$

      transform (II):
      $$
      12=frac{20}{1+2e^r} iff 12(1+2e^{r})=20 iff 24e^{r}=8 iff e^r=frac{1}{3} iff r=lnleft(frac{1}{3}right)
      $$

      So
      $A=20$ and $r=ln(frac{1}{3})approx -1.0986$. (III) is not needed for this.






      share|cite|improve this answer











      $endgroup$
















        1












        1








        1





        $begingroup$

        From the given form $f=frac{A}{1+2e^{rx}}$ and by checking the points on the graph we get
        $$begin{aligned}
        10&=f(0)=frac{A}{0+2e^{rcdot0}}=frac{A}{2} implies A=20 &&(text{I})\
        12&=f(1)=frac{A}{1+2e^{rcdot1}}overset{text{(I)}}{=}frac{20}{1+2e^r} &&text{(II)}\
        9&=f(2)=frac{A}{2+2e^{rcdot2}}overset{text{(I)}}{=}frac{10}{1+e^{2r}} &&text{(III)}\
        end{aligned}$$

        transform (II):
        $$
        12=frac{20}{1+2e^r} iff 12(1+2e^{r})=20 iff 24e^{r}=8 iff e^r=frac{1}{3} iff r=lnleft(frac{1}{3}right)
        $$

        So
        $A=20$ and $r=ln(frac{1}{3})approx -1.0986$. (III) is not needed for this.






        share|cite|improve this answer











        $endgroup$



        From the given form $f=frac{A}{1+2e^{rx}}$ and by checking the points on the graph we get
        $$begin{aligned}
        10&=f(0)=frac{A}{0+2e^{rcdot0}}=frac{A}{2} implies A=20 &&(text{I})\
        12&=f(1)=frac{A}{1+2e^{rcdot1}}overset{text{(I)}}{=}frac{20}{1+2e^r} &&text{(II)}\
        9&=f(2)=frac{A}{2+2e^{rcdot2}}overset{text{(I)}}{=}frac{10}{1+e^{2r}} &&text{(III)}\
        end{aligned}$$

        transform (II):
        $$
        12=frac{20}{1+2e^r} iff 12(1+2e^{r})=20 iff 24e^{r}=8 iff e^r=frac{1}{3} iff r=lnleft(frac{1}{3}right)
        $$

        So
        $A=20$ and $r=ln(frac{1}{3})approx -1.0986$. (III) is not needed for this.







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Dec 17 '18 at 22:29

























        answered Dec 17 '18 at 12:27









        quiliupquiliup

        1799




        1799






























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