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onegirl
Group Title
A person scores f(x) = 90/1 + 4e^0.4t points on a test after t hours of studying. What does the person score without studying at all? Compute f’(0) and estimate how many points 1 hours of studying will add to the score.
 one year ago
 one year ago
onegirl Group Title
A person scores f(x) = 90/1 + 4e^0.4t points on a test after t hours of studying. What does the person score without studying at all? Compute f’(0) and estimate how many points 1 hours of studying will add to the score.
 one year ago
 one year ago

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onegirl Group TitleBest ResponseYou've already chosen the best response.0
This is what I did but my teacher said it was wrong she said ( Find f' and f'(0).) F(x) = 90/ 1 + 4e^0.4t F(0) = 90/ 1 + 4e^0.4(0) = 18 F(1) = 90/1 + 4e^0.4(1) = 24.45 So comparing the scote at f(1) and f(0) where at f(1) studying for 1 hour and f(0) studying none. F(1)  f(0)/24.45 – 18 = 6.45 points
 one year ago

EulersEquation Group TitleBest ResponseYou've already chosen the best response.1
Should this have parenteses or not? Is this F(x) = 90/ (1 + 4e^0.4t )?
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
yes prenthesis
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
like this \[\frac{ 9 }{ 1 + 4e ^{0.4t}}\]
 one year ago

EulersEquation Group TitleBest ResponseYou've already chosen the best response.1
Your teacher specifically said to differentiate?
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
she said to Find f' and f'(0)
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
@EulersEquation so do you know how?
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
@Numb3r1 can u help?
 one year ago

EulersEquation Group TitleBest ResponseYou've already chosen the best response.1
Yes. I need to review this. First glance is to use the quotient rule. Do you know how to use the quotient rule? Someone else may want to take a look. I am in the middle of helping someone else. When I finish I'll get on it.
 one year ago

EulersEquation Group TitleBest ResponseYou've already chosen the best response.1
Ha! I am terrible at arithmetic. On first run I get a negative number for f'(0). You cannot make a negative score on a test! Unless the teacher doesn't like you. I am rusty on this. I'll work on it some more. In the meantime, bump the problem and hopefully someone else will tackle this.
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
@waterineyes
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
Just want to take derivative of that??
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
yes Find f' and f'(0)
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
It will come out to be negative..
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
what will come out? so what i did above is wrong or?
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
Wait, let we do it first..
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
\[\frac{ 90 }{ 1 + 4e ^{0.4t}} = \frac{ (90)(1.6 \cdot e^{0.4t}) }{ (1 + 4e ^{0.4t})^2}\]
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
It will become positive now.. :)
 one year ago

EulersEquation Group TitleBest ResponseYou've already chosen the best response.1
Yeah. I don't see why it has to be differentiated  not according to the question.
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
Am I right in this?
 one year ago

EulersEquation Group TitleBest ResponseYou've already chosen the best response.1
Ah! I forgot to square the denominator!
 one year ago

EulersEquation Group TitleBest ResponseYou've already chosen the best response.1
That looks good.
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
okay thanks!
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
So you can now find f'(0) by putting 0 as value of t..
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
@onegirl can you go for that?
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
just plug in 0 and solve right?
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
Yep, just simple calculations with calculator..
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
okay yes i can
 one year ago

waterineyes Group TitleBest ResponseYou've already chosen the best response.1
Good.. Keep it up..
 one year ago

onegirl Group TitleBest ResponseYou've already chosen the best response.0
i got 0 after i solved
 one year ago
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