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onegirl
 2 years ago
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.
onegirl
 2 years ago
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.

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onegirl
 2 years ago
Best ResponseYou've already chosen the best response.0This 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

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

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

EulersEquation
 2 years ago
Best ResponseYou've already chosen the best response.1Your teacher specifically said to differentiate?

onegirl
 2 years ago
Best ResponseYou've already chosen the best response.0she said to Find f' and f'(0)

onegirl
 2 years ago
Best ResponseYou've already chosen the best response.0@EulersEquation so do you know how?

EulersEquation
 2 years ago
Best ResponseYou've already chosen the best response.1Yes. 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.

EulersEquation
 2 years ago
Best ResponseYou've already chosen the best response.1Ha! 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.

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1Just want to take derivative of that??

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1It will come out to be negative..

onegirl
 2 years ago
Best ResponseYou've already chosen the best response.0what will come out? so what i did above is wrong or?

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1Wait, let we do it first..

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

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1It will become positive now.. :)

EulersEquation
 2 years ago
Best ResponseYou've already chosen the best response.1Yeah. I don't see why it has to be differentiated  not according to the question.

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1Am I right in this?

EulersEquation
 2 years ago
Best ResponseYou've already chosen the best response.1Ah! I forgot to square the denominator!

EulersEquation
 2 years ago
Best ResponseYou've already chosen the best response.1That looks good.

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1So you can now find f'(0) by putting 0 as value of t..

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1@onegirl can you go for that?

onegirl
 2 years ago
Best ResponseYou've already chosen the best response.0just plug in 0 and solve right?

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1Yep, just simple calculations with calculator..

waterineyes
 2 years ago
Best ResponseYou've already chosen the best response.1Good.. Keep it up..
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