Please turn on javascript in your browser to play chess.
Posers and Puzzles

Posers and Puzzles

  1. Standard member genius
    Wayward Soul
    15 Jan '05 16:23
    tricky little trig problem that i found today. that is, it was in my exam...woo...

    show that tan(3x) = (3*tan(x)-tan(x)^3)/(1-3*(tan(x)^2)
  2. 15 Jan '05 23:31
    Originally posted by genius
    tricky little trig problem that i found today. that is, it was in my exam...woo...

    show that tan(3x) = (3*tan(x)-tan(x)^3)/(1-3*(tan(x)^2)
    wtf??? ... and I felt bad because I messed up my physics exam on thursday (that is, really messed it up as in nearly every question wrong...). Did you get the right answer in the exam, btw?
    Angie

    PS: I hate physics... and I have a maths exam on tuesday, so I'll just ask you if I have questions beforehand
  3. Donation Acolyte
    Now With Added BA
    16 Jan '05 00:31 / 1 edit
    Originally posted by genius
    tricky little trig problem that i found today. that is, it was in my exam...woo...

    show that tan(3x) = (3*tan(x)-tan(x)^3)/(1-3*(tan(x)^2)
    Use the formula for tan(A+B) ( (tanA + tanB)/(1-tanAtanB) or something) and turn the handle - standard Higher/A-Level question.
  4. Standard member genius
    Wayward Soul
    16 Jan '05 12:04
    Originally posted by Acolyte
    Use the formula for tan(A+B) ( (tanA + tanB)/(1-tanAtanB) or something) and turn the handle - standard Higher/A-Level question.
    erm-i meant to add in "using De Moivres theorem". sorry