1.   Use the sum or difference identity for sine to find the exact value
of sin 375°.
    A. B.
    C. D.
    Hint

  2.   Use the sum or difference identity for tangent to find the exact value
of tan 255°.
    A. B.
    C. D.
    Hint

  3.   Use the sum or difference identity for tangent to find the exact value of tan 165°.
    A. 1 B. -
    C. D. - 2
    Hint

  4.   Find the value of cos (x - y) if 0 < x < , 0 < y < , sin x = , and cos y = .
    A. B.
    C. D.
    Hint

  5.   Complete the identity tan ( - A) = ________.
    A. tan A B. -tan A
    C. cot A D. -cot A
    Hint