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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.
 11 months ago
 11 months 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.
 11 months ago
 11 months ago

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onegirlBest 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
 11 months ago

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

onegirlBest ResponseYou've already chosen the best response.0
like this \[\frac{ 9 }{ 1 + 4e ^{0.4t}}\]
 11 months ago

EulersEquationBest ResponseYou've already chosen the best response.1
Your teacher specifically said to differentiate?
 11 months ago

onegirlBest ResponseYou've already chosen the best response.0
she said to Find f' and f'(0)
 11 months ago

onegirlBest ResponseYou've already chosen the best response.0
@EulersEquation so do you know how?
 11 months ago

EulersEquationBest 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.
 11 months ago

EulersEquationBest 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.
 11 months ago

waterineyesBest ResponseYou've already chosen the best response.1
Just want to take derivative of that??
 11 months ago

onegirlBest ResponseYou've already chosen the best response.0
yes Find f' and f'(0)
 11 months ago

waterineyesBest ResponseYou've already chosen the best response.1
It will come out to be negative..
 11 months ago

onegirlBest ResponseYou've already chosen the best response.0
what will come out? so what i did above is wrong or?
 11 months ago

waterineyesBest ResponseYou've already chosen the best response.1
Wait, let we do it first..
 11 months ago

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

waterineyesBest ResponseYou've already chosen the best response.1
It will become positive now.. :)
 11 months ago

EulersEquationBest ResponseYou've already chosen the best response.1
Yeah. I don't see why it has to be differentiated  not according to the question.
 11 months ago

waterineyesBest ResponseYou've already chosen the best response.1
Am I right in this?
 11 months ago

EulersEquationBest ResponseYou've already chosen the best response.1
Ah! I forgot to square the denominator!
 11 months ago

EulersEquationBest ResponseYou've already chosen the best response.1
That looks good.
 11 months ago

waterineyesBest ResponseYou've already chosen the best response.1
So you can now find f'(0) by putting 0 as value of t..
 11 months ago

waterineyesBest ResponseYou've already chosen the best response.1
@onegirl can you go for that?
 11 months ago

onegirlBest ResponseYou've already chosen the best response.0
just plug in 0 and solve right?
 11 months ago

waterineyesBest ResponseYou've already chosen the best response.1
Yep, just simple calculations with calculator..
 11 months ago

waterineyesBest ResponseYou've already chosen the best response.1
Good.. Keep it up..
 11 months ago

onegirlBest ResponseYou've already chosen the best response.0
i got 0 after i solved
 11 months ago
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