7. find tan 120 by using the functions of 60 8. find cos 60° by using the functions of 30°. in exercises 9-14, use a calculator to verify the values found by using the double-angle formulas. 9. find sin 258° directly and by using functions of 129° 10. find tan 184° directly and by using functions of 92 11. find cos 96° directly and by using functions of 48° 12. find cos 276° directly and by using functions of 138°. 13. find tan directly and by using functions of 3. 14. find sin 1.27t directly and by using functions of 0.67r.