18. Find the exact value of cos[315). (I point) 5 J2' T 19. Which trigonometric function has the same value as sin 38? (1 point) cos 38 cos 52 sin 52 tan 38 20. Determine the quadrant for an angle with the following characteristics: not a :: III and :5: 6' :2 III (1 point) Quadrant I Quadrant II Quadrant III Quadrant IV 21- Find the reference angle for the angle 3?\" . (I point) i\" 3 f 4 f 3 :_r 6 22- Find the exact value of sec 0 if cs: 5' = i and and the terminal side of 6 lies in Quadrant III. (I point) 3 SECS:i 5 7 semi):2 4 sec9= 4 23. Explain how to nd the reference angle for L406". Find the reference angle. (2 points)