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Finding zero of function problem please help

  • Thread starter marcuss
  • Start date
  • #1
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Homework Statement



the function f(x)=tan(3^x) has one zero in the interval [0,1.4]. The derivative at this point is


The Attempt at a Solution



f'(x)= sec^2(3^x)*x3^(x-1) and i really cant seem to get a zero from that because i really dont know where to start and if im misinterpreting the problem please tell me that. Thanks
 

Answers and Replies

  • #2
166
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Wait, what is the initial question?
Are you trying to find roots of:

[tex]y=\tan{(3^x})[/tex]
http://img7.imageshack.us/img7/7748/tan3x.jpg [Broken]
 
Last edited by a moderator:
  • #3
166
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If that's the case, your derivative is incorrect.

[tex]f'(x) = 3^x \log(3) \sec^2({3^x})[/tex]
 

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