Pre-Calc/Math

posted by .

Prove Identity: (1-cos2x/ tan x) = sin2x

  • Pre-Calc/Math -

    I think the parentheses are in the wrong place. It should probably read:

    (1-cos2x)/tan x = sin2x

    Again, split everything into sin and cos, and don't forget the identities:
    cos(2x)=cos²(x)-sin²(x)
    sin(2x)=2sin(x)cos(x)

    (1-cos(2x))/tan(x)
    =(1-(cos²(x)-sin²(x))*(cos(x)/sin(x))
    =(1-(1-2sin²(x))*cos(x)/sin(x)
    =2sin²(x)*cos(x)/sin(x)
    =2sin(x)cos(x)
    =sin(2x)

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. calc

    Where do I start to prove this identity: sinx/cosx= 1-cos2x/sin2x please help!! Hint: Fractions are evil. Get rid of them. Well, cos2x = cos 2 x - sin 2 x, so 1-coscx = 1 - cos 2 x - sin 2 x = 1 - cos 2 x + sin 2 x You should be able …
  2. Math

    Required to Prove the following trig identity: (cos2x)^2 + (sin2x)^2 = 1
  3. gr 12. advanced functions

    Trig identity Prove: cos2x tan(pie/4 - x) ------- = 1 + sin2x
  4. Calculus

    Solve identity, (1-sin2x)/cos2x = cos2x/(1+sin2x) I tried starting from the right side, RS: =(cos²x-sin²x)/(1+2sinxcosx) =(cos²x-(1-cos²x))/(1+2sinxcosx) and the right side just goes in circle. May I get a hint to start off?
  5. Pre-Calc (Prove the identity)

    Prove the identity. (show your work please) tan(x − π/4)= (tan x − 1)/(tan x + 1) Thank you!
  6. Pre-Calc Help!!!

    Prove the identity. (show your work please) tan(x − π/4)= (tan x − 1)/(tan x + 1) Thank you!
  7. Pre-Calc (Prove the identity)

    Prove the identity. (show steps please!) Thank you! tan^2(x/2+π/4)=(1 + sin x)/(1 − sin x)
  8. Math

    prove sin2x+cos2x+1 tan(pi/4+x) ______________ = __________ sin2x+cos2x-1 tanx so what I did tan(x) (1+cos(2x)+sin(2x)=tan(pi/4+x) (-1+cos(2x)+sin(2x)
  9. Pre-calculus

    prove the identity sin2x-sin2y/sin2x+sin2y=tan(x-y)/tan(x+y)
  10. Pre calc

    Please help me proof the identity. This isn't even math to me, I can not understand it so please show all work. God bless A)1-cos2x/sin2x=tanx B) sin4x/sinx=4cosxcos2x

More Similar Questions