Results 1 to 7 of 7

Math Help - first expression of the second

  1. #1
    Member
    Joined
    Sep 2009
    Posts
    181

    first expression of the second

    Hello,

    Can someone please help me with this problem?

    Here's the instructions:
    Write the first expression in terms of the second if the terminal point determined by t is in the given quadrant.

    Problem:

    sec^2(t)sin^2(t), cos (t) ; any quadrant

    Thanks!
    -Mark
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Mar 2007
    Posts
    1,240

    Talking

    Use the fact that sec(x) = 1/cos(x) and that sin^2(x) + cos^2(x) = 1.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Sep 2009
    Posts
    181
    if that's the case, would the answer be

    sec^2 = 1/sqrt(1-sin^2)
    Follow Math Help Forum on Facebook and Google+

  4. #4
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    12
    Awards
    1
    Quote Originally Posted by l flipboi l View Post
    Hello,

    Can someone please help me with this problem?

    Here's the instructions:
    Write the first expression in terms of the second if the terminal point determined by t is in the given quadrant.

    Problem:

    sec^2(t)sin^2(t), cos (t) ; any quadrant

    Thanks!
    -Mark
    Quote Originally Posted by l flipboi l View Post
    if that's the case, would the answer be

    sec^2 = 1/sqrt(1-sin^2)
    Hi I flipboi l,

    Using what Stapel told you....

    \sec^2(t) \sin^2(t)=\frac{1}{\cos^2(t)}\cdot 1-\cos^2(t)=\frac{1-\cos^2(t)}{\cos^2(t)}=\frac{1}{\cos^2(t)}-1
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Sep 2009
    Posts
    181
    Great!

    I was wondering though, for the sec^2 (t) sin^2 (t)...why is there a sin^2 (t) there? what's it's purpose?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    12
    Awards
    1
    Quote Originally Posted by l flipboi l View Post
    Great!

    I was wondering though, for the sec^2 (t) sin^2 (t)...why is there a sin^2 (t) there? what's it's purpose?
    I have no idea. Where did the expression originate? Is it an exercise in a textbook? Looks like this is an exercise in manipulating trigonometric expressions. Good practice, though.
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Member
    Joined
    Sep 2009
    Posts
    181
    Quote Originally Posted by masters View Post
    I have no idea. Where did the expression originate? Is it an exercise in a textbook? Looks like this is an exercise in manipulating trigonometric expressions. Good practice, though.
    yeah it came from the book. I'm trying to understand what sin^2(t) has to do with sec^2 (t) and why they're together.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 20
    Last Post: January 15th 2012, 09:30 AM
  2. Replies: 6
    Last Post: October 6th 2011, 01:48 PM
  3. An expression for a sum
    Posted in the Calculus Forum
    Replies: 4
    Last Post: June 7th 2009, 06:58 PM
  4. Expression in a+bi
    Posted in the Algebra Forum
    Replies: 1
    Last Post: January 25th 2009, 03:49 PM
  5. DNF expression HELP!
    Posted in the Discrete Math Forum
    Replies: 3
    Last Post: May 5th 2008, 09:29 PM

Search Tags


/mathhelpforum @mathhelpforum