Find the exact value of each expression. (Do not use a calculator.)

cos 105° (Hint: 105° = 60° + 45°)

Find the exact value of each expression. (Do not use a calculator.)

cos π/12

Find the exact value of each expression. (Do not use a calculator.)

cos (-7π/12)

Find the exact value of each expression. (Do not use a calculator.)

cos (7π/9) cos (2π/9) - sin (7π/9) sin (2π/9)

Write each function value in terms of the cofunction of a complementary angle.

sin (2π/5)

Write each function value in terms of the cofunction of a complementary angle.

sin 142° 14'

Write each function value in terms of the cofunction of a complementary angle.

cot (9π/10)

Write each function value in terms of the cofunction of a complementary angle.

tan 174° 03'