Tiêu đề 6. Trigonometric Ratios Engineering Practice Sheet Solution [HSC 26].pdf ✅

w·KvYwgwZK AbycvZ  Engineering Practice Sheet Solution (HSC 26) 3 e ̈vL ̈v: cos2  = (a + b) 2 4ab a = b n‡j, cos2  = (2a) 2 4a.a = 4a2 4a2 = 1  cos =  1   = 0, 180, ............ weMZ mv‡j RUET-G Avmv cÖkœvewj 9. †Kv‡bv wÎfz‡Ri f~wg msjMœ †KvYØq 22.5 I 112.5 Ges wÎfz‡Ri D”PZv h n‡j f~wg KZ? [RUET 14-15] h 2h h 2 h 2 DËi: 2h e ̈vL ̈v: 22.5 45 90 67.5 112.5 22.5 A h B C D awi, AB = h ACD = 112.5, ACB = 67.5, BAC = 22.5 CAD = 45, ADC = 22.5, BAD = 67.5 tanACB = AB BC  BC = AB tan67.5 = h tan67.5  CD = BD – BC = h tan22.5 – h tan67.5 = 2h ----