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avatar+2448 

Please help asap im confused

 Sep 17, 2018
 #1
avatar+128079 
+2

We want to find where  p(t)    =  0    [  no population  remains  ] 

 

So

 

0  = -t^4  + 72t^2  + 225     multiply through  by  -1  and rearrange

 

t^4 - 72t^2  - 225   = 0       this will factor as

 

(t^2  - 75) (t^2  + 3)  = 0

 

When set to  0  and solved for t, the second factor produces a non-real answer

 

For...the first factor we have

 

t^2  - 75  =0      add 75 to both sides

 

t^2   =  75   take the positive root

 

t ≈   8.66 years

 

 

cool cool cool

 Sep 17, 2018
 #2
avatar+2448 
+1

Thank you so much!

RainbowPanda  Sep 17, 2018

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