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anonymous

  • 5 years ago

Amistre64, are you out there? I need help! the question is: find the absolute maximum and minimum values of the function in given interval. f(theta)=cos theta -2less than or equal to theta less than or equal to -3pi/4.

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  1. amistre64
    • 5 years ago
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    im out here somewhere in the eternal ether :)

  2. anonymous
    • 5 years ago
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    Actually, i typed some of that wrong. It's the interval of -2pi less than or equal to theta less than or equal to -3pi/4

  3. amistre64
    • 5 years ago
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    its a simple cos function.... nothing modifying it so it should be easy for us to accomplish :)

  4. anonymous
    • 5 years ago
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    Just fyi i know NOTHING about converting thetas to square roots.

  5. amistre64
    • 5 years ago
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    -2pi to 0 has a max at 0; a max at -2pi and a min at pi this is just pointing out where the graph bends at between -2pi and -3pi/4 which i went a little far

  6. amistre64
    • 5 years ago
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    -2pi = max - pi = min and that all you get in that interval

  7. anonymous
    • 5 years ago
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    I don't get it. Where are the max and min values in that? I know nothing abou this!

  8. amistre64
    • 5 years ago
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    the cosine graph is just a wave that bounces between 1 and -1

  9. amistre64
    • 5 years ago
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    at 0 or any even multiples of pi; cos(x) = 1 at pi or any odd multiples cos(x) = -1

  10. anonymous
    • 5 years ago
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    How did you figure that out? What is the actual value of the max at -2pi? and -pi? Aren't they like answers in terms of square roots or pi or something?

  11. amistre64
    • 5 years ago
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    we could take the derivative which is -sin(x) but that doesnt help out much unless you know the graph for it as well :)

  12. amistre64
    • 5 years ago
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    nah; the max of cos(x) = 1 the min of cos(x) = -1

  13. amistre64
    • 5 years ago
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    cos(-2pi) = 1 cos(-pi) = -1

  14. amistre64
    • 5 years ago
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    thats just the definition for cosine...

  15. amistre64
    • 5 years ago
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    Dx(cos(x)) = -sin(x) -sin(x) = 0 at..... -2pi, and -pi in between [-1pi,-3pi/4]

  16. anonymous
    • 5 years ago
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    Ok, here's how they want the answer and I can't figure out what you are telling me. They want "Absolute maximum is ____ at theta=_____

  17. anonymous
    • 5 years ago
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    Then "Absolute minimum is ____ at theta=____"

  18. amistre64
    • 5 years ago
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  19. amistre64
    • 5 years ago
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    absolute min = -1 at -pi

  20. amistre64
    • 5 years ago
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    absolute max = 1 at -2pi

  21. anonymous
    • 5 years ago
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    Bless you, dear. But HOW DO YOU KNOW THIS? is there a table of values? I just started this in calculus, and I am sure i will need it in the future, and unless you want to take my next calc exam... seriously where i find the equations for this? Like what does sin(5pi/3 equal? Where do I find those values or is there a conversion with a formula?

  22. amistre64
    • 5 years ago
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    its from trig class; trig is just memorizing angles and sin cos tan stuff

  23. anonymous
    • 5 years ago
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    ok but where do you find the angles to memorize? Like i said, is there a table or something? A formula? What? there has to be some way to figure this out!!!!!

  24. amistre64
    • 5 years ago
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    yeah, look up 'trig tables' and 'trig graphs' in google; theyll give you alot to pick from :)

  25. anonymous
    • 5 years ago
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    ok, btw, not that you doubted your brain power or anything, but of course you were right and figured out in 3 seconds what i have been trying to figure out for literally 43 hours. 1 problem...3 hours??? I can't do that for 50 problems!!! These tables will help?

  26. anonymous
    • 5 years ago
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    i did not mean 43 hours, i meant 3

  27. amistre64
    • 5 years ago
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    :) they will help. And when i dont use trig for a while im bound to forget them ;)

  28. anonymous
    • 5 years ago
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    do you do this math stuff for fun? because you love it so much? you must because you don't get paid to help dummies like me!!! ; )

  29. amistre64
    • 5 years ago
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    lol... i do enjoy math; its the one constant in my life :)

  30. anonymous
    • 5 years ago
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    yay for you. i enjoy it too, more on the algebra end, but i am not good at it naturally; I struggle to learn it. Trying to take a calc course online is like literally teaching myself everything there is to know about calc! Not sure I will be as successful as you are at it!

  31. amistre64
    • 5 years ago
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    ive taught myself up to about calc4 so far; its easy once you get past the tedium of limits and longhand version of derivatives and integrals

  32. amistre64
    • 5 years ago
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    well, derivatives are pretty straight forward; integrals can be tricky because its more art than science

  33. anonymous
    • 5 years ago
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    oh my gosh. I could only wish to be that smart! Thank you so much! I don't know wht time it is there, but it is almost 3 am here in Illinois and I have to be up with the kids in like 3 hours1 This math will literally be the death of me! Thank you thank you thank you again and again! I'm sure i will talk to to you VERY soon. Rachel.

  34. anonymous
    • 5 years ago
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    Good night, and thanks again.

  35. amistre64
    • 5 years ago
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    Nite , im in florida ;)

  36. anonymous
    • 5 years ago
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    So its like almost 4 am there!

  37. amistre64
    • 5 years ago
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    illinois is one of them mormon states i believe

  38. amistre64
    • 5 years ago
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    330am if the computer is right ;)

  39. anonymous
    • 5 years ago
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    yes it is it's 2:30 here. crazy!

  40. anonymous
    • 5 years ago
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    ttyl, thanksoncemore

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