Results are out! Find what you need...fast. Get quick advice or join the chat
x

Unlock these great extras with your FREE membership

  • One-on-one advice about results day and Clearing
  • Free access to our personal statement wizard
  • Customise TSR to suit how you want to use it

Core 3- Trig

Announcements Posted on
Rate your uni — help us build a league table based on real student views 19-08-2015
  1. Offline

    ReputationRep:
    [sec(x) - 1 ]/tan(x) = [ tan (x)]/ sec(x) +1

    So, i have to prove this identity is true. Ive managed to show it by dividing both sides by one of the sides, however i cant think how to start from either the left or right, and work myself to the other side. Any help would be awesome
  2. Offline

    ReputationRep:
    \frac{sec-1}{tan} = [\frac{1}{cos} - 1]\frac{cos}{sin} = \frac{1-cos}{sin} = \frac{1-cos^2}{sin(1+cos)} = \frac{sin}{1+cos} = \frac{tan}{sec+1}
  3. Offline

    ReputationRep:
    (Original post by antonio108)
    [sec(x) - 1 ]/tan(x) = [ tan (x)]/ sec(x) +1

    So, i have to prove this identity is true. Ive managed to show it by dividing both sides by one of the sides, however i cant think how to start from either the left or right, and work myself to the other side. Any help would be awesome
     \displaystyle \frac{secx-1}{tanx} \equiv \frac{tanx}{secx+1}

    LHS =
     \displaystyle \frac{secx-1}{tanx} = \frac{\frac1{cosx}-1}{\frac{sinx}{cosx}} = \frac{\frac{1-cosx}{cosx}}{\frac{sinx}{cosx}}=  \frac{1-cosx}{sinx}=\frac{(1-cosx)(1+cosx)}{sinx(1+cosx)}}
     \displaystyle \frac{sin^2x}{sinx(1+cosx)} = \frac{sinx}{1+cosx}=\frac{\frac{  sinx}{cosx}}{\frac{1+cosx}{cosx}  }=\frac{tanx}{secx+1}
  4. Offline

    ReputationRep:
    Several methods, here is mine.




    Uploaded with ImageShack.us
  5. Offline

    ReputationRep:
    Ah thank you very much, just looking through and slowly realising what i have to look out for.
    Again, thanks!

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: April 6, 2012
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

New on TSR

Rate your uni

Help build a new league table

Poll
How soon after finishing your degree did you get a job offer
Study resources
Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.