Question

2. Find exact values for sin(20), cos(20), tan(20) using the information given. (a) cos(6) = -2; in QII (b) tan(8) = in QIII (c) sin(Ⓡ) = .in QIV

Answer 1

o in (a) when costs- Q IL tan o= Sino coso sine = (1-1-32 289-64 17 17 -715 in & II, sino =+ 15 - Sin (20) = 2 sing-coso = 2.17 18:1-3) 240 289 cos (20) = 2605²on1 = 2 ( 24 ) 2 , = 2x64 - 1 li 289 128-289 289 161 289

tanao - Sinko) COS(20) - 240 289 161 289 240 161 - 165 tano = when o in QIEL Sino) - 2 tano It zanza 2x 11o 3600 - 3721 22 x 60 3721 1320 3721

- tanto 1- (2) - T+ ? (60) 2 (11) 2 som (60)2 360o-121 3600 + 12 1 3479 3721 Sinze los 26 tanzo 1320 1320 3721 3479 3721 3479 (C) sino = -21 13 , 0 in Glv case = ST - (-452 = [(53)²-(45) ² 53 2809-2025 53 V 784 53

ino. QIY, Cose = + 283 sin 20 = 2. sine cost = 2049 (28 cos20=2 costo - 1 = 2X (28) 2 - 1 - (2 x 784)- 2809 2809 1568-2809 2809 - -1241 2809 - 2520 2520 2809 2520 124 T tan 20 - tom 20 sinzo Corzo - 124! 220g