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Thread: Saoirse's Primal Journal page 199

  1. #1981
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    oh wow. i solved that problem without even realizing it was THE problem. i had written it again in my notebook and left space so i could ask the professor tomorrow and write it down, and tonight i was just finishing up the half-finished problems when i completed that one and realized it was THE one. lol. but yeah, magicmerl, i think that's an apt description of what we have been doing so far. i have been wondering if i'm having such a hard time with this because i don't "get" the professor's teaching style. another classmate noted this, it seems that he makes things unnecessarily complex. but it may just be that i'm having a hard time and need to study more, who knows. if you want to give it a whack, the original problem is above (and rewritten below).

    tan[2arccos(-3/5)]=?
    (don't use a calculator of course)
    Last edited by Saoirse; 07-02-2012 at 01:00 AM.

  2. #1982
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    Yes, I think the teacher expected displacement.

  3. #1983
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    What I found as an engineer is that I never needed the calc. - never! Real life often has enough of the variables determined and things break down into basic algebra or maybe geometry. Trig is definitely needed to understand calc. Another problem is that many of the teachers teaching calc don't have a firm grasp of it themselves and can get intimidated by the students who do. I love that you solved the problem after taking a break as this is a technique I have found to work often for me in most stumpers that life throws my way. The other wonderful thing I've found is that school makes so much more sense once you have some life experience to add to it. My grad school work was so much less frustrating as I knew what was important and what was fluff.

  4. #1984
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    Mud flinger- i didn't realize you're an engineer! engineer friend of mine says that he uses polynomial equations often, but that's not a problem for me. I do have a different perspective now than when i was straight out of high school. i think, then, i would've been so intimidated by the idea of being a professional anything, it may have become a hang-up when i encountered difficulties with my studies. now, i know a number of people who ARE engineers who are otherwise easy-going, cool people, that it's not such an intimidating factor for me. Sometimes people are smarter than you think, but the way i see it is that if they could get through it, i should be able to also. the cool thing about my school is that it's a small engineering school; almost everyone is a geek of some sort (M:F ratio is 5:1) and both expectations of students and expectations of the staff are higher. so far i haven't had to deal with much of the inanity that i've heard goes on in other universities or colleges.

  5. #1985
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    What I found as an engineer is that I never needed the calc. - never!
    Yeah. And statistics always seemed like such a waste of time at school / university, but it has a lot of real world implications.

    Although the most important is understanding compound interest...

    Quote Originally Posted by Saoirse View Post
    oh wow. i solved that problem without even realizing it was THE problem. i had written it again in my notebook and left space so i could ask the professor tomorrow and write it down, and tonight i was just finishing up the half-finished problems when i completed that one and realized it was THE one. lol. but yeah, magicmerl, i think that's an apt description of what we have been doing so far. i have been wondering if i'm having such a hard time with this because i don't "get" the professor's teaching style. another classmate noted this, it seems that he makes things unnecessarily complex. but it may just be that i'm having a hard time and need to study more, who knows. if you want to give it a whack, the original problem is above (and rewritten below).

    tan[2arccos(-3/5)]=?
    (don't use a calculator of course)
    tan[2 arccos(-3/5)]
    = tan[2 (2 arctan((1-9/25)/(1-3/5)))]
    = tan[2 (2 arctan((16/25)/(2/5)))]
    = tan[4 arctan(8/5)]

    And then my brain went soft. Presumably there's some tan/arctan interaction that I'm missing. Back to work....

    Yay for you on finally solving it!
    Last edited by magicmerl; 07-02-2012 at 04:51 PM.
    Disclaimer: I eat 'meat and vegetables' ala Primal, although I don't agree with the carb curve. I like Perfect Health Diet and WAPF Lactofermentation a lot.

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    bloodorchid is always right

  6. #1986
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    yes, you can cancel tan[arctan] so the answer would be 8/5, but you must've made an error somewhere because the answer was 24/7. the goal basically is to use the right formulas so you can cancel out the inverse trig function to get theta.

    83.jpg

    of course i have this handy cheat sheet of relevant formulas. :P

    oops, the -8/5 should be +8/5.
    Last edited by Saoirse; 07-02-2012 at 05:25 PM.

  7. #1987
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    Quote Originally Posted by zoebird View Post
    My friend's son (age 10) was set to the task of determining the volume of an orange. I thought this was an interesting project, but then my husband looked at me and said "that requires calculus."
    it does? Isn't an orange basically a sphere? V= 4/3 pi*r^3 (sorry, I can't do the little symbol for pi)

    I know oranges are not perfect spheres but I can't imagine they expected calculus for a 10 year old.

  8. #1988
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    Nice.
    Disclaimer: I eat 'meat and vegetables' ala Primal, although I don't agree with the carb curve. I like Perfect Health Diet and WAPF Lactofermentation a lot.

    Griff's cholesterol primer
    5,000 Cal Fat <> 5,000 Cal Carbs
    Winterbike: What I eat every day is what other people eat to treat themselves.
    TQP: I find for me that nutrition is much more important than what I do in the gym.
    bloodorchid is always right

  9. #1989
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    Test tomorrow, btw.

  10. #1990
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    Primal Blueprint Expert Certification
    You'll nail it.
    Disclaimer: I eat 'meat and vegetables' ala Primal, although I don't agree with the carb curve. I like Perfect Health Diet and WAPF Lactofermentation a lot.

    Griff's cholesterol primer
    5,000 Cal Fat <> 5,000 Cal Carbs
    Winterbike: What I eat every day is what other people eat to treat themselves.
    TQP: I find for me that nutrition is much more important than what I do in the gym.
    bloodorchid is always right

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