Results 1 to 3 of 3

Math Help - Need help with some easy trig + integral

  1. #1
    Member
    Joined
    Nov 2008
    Posts
    146

    Need help with some easy trig + integral

    Hi,

    I've pretty much forgotten all my trig, so heres a really basic question if anyone can help.

    I have to find the following integral:

    upper bound = 1, lower bound = 0

    integral: 16 ((sec(x))^2/x^3/2)

    I have to use the comparison theorem to do this and so far this is what i did.
    I used the identity sec(x) = 1/cos(x)

    so subbing that in it would be (1/cos(x))^2/x^3/2

    now heres the really stupid question
    if i squared cos(x), what would be the result? cos^2(x) or cos(x^2) ??
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member General's Avatar
    Joined
    Jan 2010
    From
    Kuwait
    Posts
    562
    Is this your integral? : \displaystyle 16 \int_0^1 \frac{(sec(x))^2}{  \left( \frac{x^3}{2} \right) } \, dx

    And you want to evaluate it (if it converges) or just test its convergence?

    -------------------------------------------------------------------------------

    Quote Originally Posted by Kuma View Post
    if i squared cos(x), what would be the result? cos^2(x) or cos(x^2) ??
    It will be : cos^2(x)=(cos(x))^2 \not= cos\left(x^2\right)
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Nov 2008
    Posts
    146
    i just want to test if it converges. The denominator is x^1.5 = x^3/2 = x sqrt x. The rest is correct.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Another easy trig. problem...
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: February 17th 2011, 08:29 PM
  2. Easy trig integral =/
    Posted in the Calculus Forum
    Replies: 5
    Last Post: February 5th 2011, 03:30 PM
  3. Easy trig question
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: October 28th 2010, 04:51 PM
  4. Easy Easy Trig help
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: November 28th 2009, 12:09 AM
  5. really easy trig question
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: August 31st 2005, 04:37 AM

Search Tags


/mathhelpforum @mathhelpforum