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How to determine the point of intersection of sine and cosine?

  • Thread starter linuxux
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  • #1
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Homework Statement



Im not sure how to start this question: determine the points of intersection between [tex]y=sin x[/tex] and [tex]y=cos 2 x[/tex] for x between 0 and pi.

The Attempt at a Solution



First thing that comes to mind is the eqaute the two, but i dont know how that helps me?
 

Answers and Replies

  • #2
dextercioby
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It should help you. And the identities regarding the sin and cos functions should help you more...
 
  • #3
HallsofIvy
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Particularly an indentity that says cos(2x) is equal to something.
 
  • #4
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thanks ive got it now, but is the only point of intersection in the range at [tex]\frac{\pi}{2}[/tex]? i suppose i could graph it to be sure...
 
Last edited:
  • #6
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okay, i was solving incorrectly, they will also both be at [tex]30^{o}[/tex]. i also assumed i would get a "nice" number. thanks.
 
Last edited:

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