Precalculus with Trigonometry

posted by .

Prove or disprove the following identity:

cos (x+pi/6) +sin (x-pi/3) = 0

  • Precalculus with Trigonometry -

    I will use 30° and 60° , easier to type
    cos (x+300) +sin (x-60)
    = cosxcos30 - sinxsin30 + sinxcos60 - cosxsin60
    = (√3/2)cosx - (1/2)sinx + (1/2)sinx - (√3/2)cosx
    = 0
    = RS

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Trigonometry

    Prove the identity sin(x+y+z)+sin(x+y-z)+sin(x-y+z)+ sin(x-y-z) = 4 sin(x)cos(y)cos(z) This identity is so long and after i tried to expand the left side and it just looked something crap Thanks for you help :)
  2. Precalc

    Prove or disprove the following identity. cos(-x) - sin(-x) = cos(x) + sin(x)
  3. Trig Identity

    Prove or disprove the following identity sin^4theta - cos^4theta = sin^2theta-cose^2theta
  4. Precalculus

    Prove or disprove cos(x+y)cos(x-y)=cos squared (x) - Sin squared (x) I dstributed the cosines and attempted to cancel out terms but I can't get the signs right. Any help on what I am missing?
  5. Trigonometry

    1.Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. 6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y 10.Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that …
  6. Precalculus with Trigonometry

    Prove or disprove the following identity: (sin(10x))/(sin(x)+sin(9x)) = (cos(5x))/(cos4x))
  7. Precalculus with Trigonometry

    Prove or disprove the following Identities: cos(-x) - sin(-x) = cos(x) + sin (x) sin raised to the 4 (theta) - cos raised to the 4 (theta) = sin squared (theta) - cos squared (theta) cos (x+(pi)/(6)) + sin (x - (pi)/(3)) = 0 cos(x+y)cos(x-y) …
  8. precalculus

    For each of the following determine whether or not it is an identity and prove your result. a. cos(x)sec(x)-sin^2(x)=cos^2(x) b. tan(x+(pi/4))= (tan(x)+1)/(1-tan(x)) c. (cos(x+y))/(cos(x-y))= (1-tan(x)tan(y))/(1+tan(x)tan(y)) d. (tan(x)+sin(x))/(1+cos(x))=tan(x) …
  9. Trigonometry desperate help, clueless girl here

    2. solve cos 2x-3sin x cos 2x=0 for the principal values to two decimal places. 3. solve tan^2 + tan x-1= 0 for the principal values to two decimal places. 4. Prove that tan^2(x) -1 + cos^2(x) = tan^2(x) sin^2 (x). 5.Prove that tan(x) …
  10. math help trigonometry

    Prove the following identity tan x cos x/sin x=1/sin x cos x

More Similar Questions