9. Use cofunction identities to help you write the expression cos 280 as the function of an acute angle of measure less than 45. 10. Use cofunction identities to help you write the expression Ian 60\" as the function of an acute angle of measure less than 45. 11. Use cofunction identities to help you write the expression sin 100\" as the function of an acute angle of measure less than 45. 12. Use cofunction identities to help you write the expression cos 70 as the function of an acute angle of measure less than 45. Evaluate the following trigonometric functions without using a calculator. Give your answers exactly. I 3 10. csc (7\") 11. cot225 12. sec