Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calc II Suggestions

  1. Sep 16, 2004 #1


    User Avatar
    Gold Member

    I skipped college albebra and trigonometry and went straight into Calculus. It was fairly easy, I had to learn trig as I went, but I got an A.

    I'm now in Calc II, using a different book through a different school (A university rather than a campus) and I'm starting to have troubles.

    Is there a book or a site or a clever system I can study that will broaden my trig understanding? I've considered just buying a trig text book from the campus bookstore.

    I've studied the unit circle a lot and played with it on my own, and I have friend that has developed an awesome diagram for multiplication and addition of trig functions, but I assume working through problems is the best thing I can do, but these books are so &%*@&$ expen$ive
  2. jcsd
  3. Sep 16, 2004 #2


    User Avatar
    Science Advisor
    Homework Helper

    the best way is to realize that trig is a special case of the exponential fuinction studied in calculus, and use that to shortcut learning trig.

    I myself skipped trig in high school and never learned the usual trig until i had to teach it. the main pooint is that e^(ix) = cos(x) +isin(x), where e^z is defiend by the powers eries e^z = 1 + z + z^2/2! + z^3/3! + z^4/4! +...... for any complex number z.

    then one defiens cos and sin by soilving the equation abovce.

    i.e. cos(x) = (1/2)[e^(ix) + e^(-ix)] and sin(x) = (1/2i)[e^(ix) - e^(-ix)].

    Then one proves that e^(x+y) = e^x e^y, and that [e^x]^y = e^[xy].

    One deduces that cos(x+y) = cos(x)cos(y) - sin(x)sin(y),

    and sin(x+y) = cos(x)sin(y) + cos(y)sin(x). (I hope)

    since also e^(2<pi>i) = 1, one concludes that cos and sin are periodic with period 2<pi>.

    tyhis reduces the compicated laws for trig functions to the simpler laws for exponential functions and makes life simpler.
  4. Sep 17, 2004 #3
    Calc 2 is tougher than Calc 1, especially in how you apply trig.... just wait for integration methods....trig plays a major role.

    I took trig in high school and did not take it seriously so when I got to college and got to calc 2 it had been about 3 years since I took my have effort trig class. I basically had to take a crash course in trig and muscle my way through. I found that the amount of trig in Calc 2 was sufficient for me to become good enough at it, and I got better as I went along. Sure, I was lost some times and I had to take a few more minutes to figure something out at first, but by the final, I knew what identities to use and how to use them.
  5. Sep 17, 2004 #4


    User Avatar
    Gold Member

    yeah, we're on trig substitution right now. I guess just doing the problems and writing down my realizations as notes is the best way to go about it.

    The power series is kind of tough to use since I haven't had much practice with it. I have a friend who showed me a bit about that, but it's sometimes just more practical to memorize things.

    The ah-ha! moment will come to me sooner or later after I memorize. I guess that's a wierd learning style, but it's what I've found works best for me, despite my hate for memorizing vs. learning
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook