Results 1 to 7 of 7

Math Help - trig: sin (θ) is 1/5. The value of cos^2 (θ) can be written.....

  1. #1
    Senior Member
    Joined
    Apr 2009
    Posts
    253

    trig: sin (θ) is 1/5. The value of cos^2 (θ) can be written.....

    The value of sin (θ) is 1/5. The value of cos^2 (θ) can be written in the form 6(α^2). Express the value of α^2 (alpha squared) as a fraction in simplest form.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Lord of certain Rings
    Isomorphism's Avatar
    Joined
    Dec 2007
    From
    IISc, Bangalore
    Posts
    1,465
    Thanks
    6
    Quote Originally Posted by yoman360 View Post
    The value of sin (θ) is 1/5. The value of cos^2 (θ) can be written in the form 6(α^2). Express the value of α^2 (alpha squared) as a fraction in simplest form.
    \cos ^2 \theta = 1 - \sin^2 \theta = 1 - \left( \frac15 \right)^2

    So if 6 \alpha ^2 = 1 - \left( \frac15 \right)^2 , what is \alpha^2?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Apr 2009
    Posts
    253
    Quote Originally Posted by Isomorphism View Post
    \cos ^2 \theta = 1 - \sin^2 \theta = 1 - \left( \frac15 \right)^2

    So if 6 \alpha ^2 = 1 - \left( \frac15 \right)^2 , what is \alpha^2?
    I don't know what it is thats why I'm asking.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Isomorphism View Post
    \cos ^2 \theta = 1 - \sin^2 \theta = 1 - \left( \frac15 \right)^2

    So if 6 \alpha ^2 = 1 - \left( \frac15 \right)^2 , what is \alpha^2?
    Quote Originally Posted by yoman360 View Post
    I don't know what it is thats why I'm asking.
    You are expected to show some effort at this stage. Where exactly are you stuck?

    Can you do the arithmetic and simplify the right hand side of that expression? After doing that, what do you think the next step will be?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Senior Member
    Joined
    Apr 2009
    Posts
    253
    Quote Originally Posted by mr fantastic View Post
    You are expected to show some effort at this stage. Where exactly are you stuck?

    Can you do the arithmetic and simplify the right hand side of that expression? After doing that, what do you think the next step will be?
    I'm sorry I wasn't really looking at it i just saw what is a^2
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Senior Member
    Joined
    Apr 2009
    Posts
    253
    Quote Originally Posted by Isomorphism View Post
    \cos ^2 \theta = 1 - \sin^2 \theta = 1 - \left( \frac15 \right)^2

    So if 6 \alpha ^2 = 1 - \left( \frac15 \right)^2 , what is \alpha^2?
    6 \alpha ^2 = (25/25) - (1/25)
    6 \alpha ^2 = 24/25
    \alpha ^2 = 4/25
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Lord of certain Rings
    Isomorphism's Avatar
    Joined
    Dec 2007
    From
    IISc, Bangalore
    Posts
    1,465
    Thanks
    6
    Quote Originally Posted by yoman360 View Post
    6 \alpha ^2 = (25/25) - (1/25)
    6 \alpha ^2 = 24/25
    \alpha ^2 = 4/25
    Well Done
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. show that y'' − y = F(t) can be written...
    Posted in the Differential Equations Forum
    Replies: 10
    Last Post: April 27th 2011, 10:19 PM
  2. Proving any function can be written in the form f = O + E ?
    Posted in the Differential Geometry Forum
    Replies: 3
    Last Post: October 6th 2010, 01:29 AM
  3. what number should be written in the brackets
    Posted in the Algebra Forum
    Replies: 7
    Last Post: July 16th 2010, 02:26 AM
  4. Replies: 3
    Last Post: October 16th 2009, 05:49 AM
  5. prooving numbers can be written a certain way
    Posted in the Number Theory Forum
    Replies: 2
    Last Post: August 20th 2008, 05:43 AM

Search Tags


/mathhelpforum @mathhelpforum