Questions on Trigonometric Identities

Multiple choice questions on trigonometric identities with answers at the bottom of the page.

  1. Question Which of the following is not an identity?

    a) sin2 a+cos2 a = 1
    b) sin a = tan a * cos a
    c) 1 + cot2 a = csc2 a
    d) 1 - sec2 a = tan2 a


  2. Question Which of the following is an identity?

    a) sin (a) cos (a) = (1/2) sin(2 a)
    b) sin a + cos a = 1
    c) sin(-a) = sin a
    d) tan a = cos a / sin a


  3. Question

    sin t + cos2 t / sin t =


    a) sin t
    b) csc t
    c) sec t
    d) cos t


  4. Question Which of the following is not an identity?

    a) tan(2 t) = 2 tan (t)
    b) sin2 a = 1 - cos2 a
    c) sin(-t) = - sin(t)
    d) sec(-t) = sec(t)


  5. Question Which of the following is an identity?

    a) sin2 u = 1 + cos2 u
    b) cot u = sin u * cos u
    c) sin2 u = 1 - 1 / sec2 u
    d) cos(-u) = - cos u


  6. Question

    sin (x) + sin(x - π) + sin(x + π) =


    a) -sin(x)
    b) sin (x)
    c) sec (x)
    d) cos (x)


ANSWERS
  1. d)
  2. a)
  3. b)
  4. a)
  5. c)
  6. a)