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GRE Practice Questionby Dustinsfl
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#1
Mar1310, 07:54 PM

P: 629

Let k be the number of real solutions of the equation e[tex]^{x}[/tex] + x  2 = 0 in the interval [0,1] and let n be the number of real solutions that are not in the interval.
By looking at the graph, I know it crosses the x axis; however, I don't remember or know how to do this problem. 


#2
Mar1310, 08:43 PM

HW Helper
Thanks
PF Gold
P: 7,659

Hint: If f(x) = e^{x} + x  2, look at f(0), f(1) and f '(x).



#3
Mar1310, 08:47 PM

P: 629

I know what f(0) and f(1) are and f '(x) = e[tex]^{x}[/tex] + 1
How is that suppose to help? 


#4
Mar1310, 09:15 PM

HW Helper
Thanks
PF Gold
P: 7,659

GRE Practice Question
What does the fact that f(0) and f(1) have opposite signs tell you? What does having a positive derivative tell you? And, of course, I'm just assuming I know what your actual question was since your original post doesn't actually contain a question. 


#5
Mar1310, 09:27 PM

P: 629

At least this isn't an English forum. The question was in regards to multiple choices so I left that out because it wasn't needed.



#6
Mar1310, 09:46 PM

HW Helper
Thanks
PF Gold
P: 7,659

How are we supposed to know what the question was if you don't tell us? So, what was the question? And did the hints I gave you help you solve it? 


#7
Mar1310, 09:48 PM

P: 629

The question said which of the following. I didn't need someone to tell me which one it was so I left it out.



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