Nội dung text Straight Line Varsity Practice Sheet Solution.pdf
mij‡iLv Varsity Practice Sheet 1 03 mij‡iLv Straight Line 1. (1, 150) we›`yi Kv‡Z©mxq ̄’vbvsK wb‡Pi †KvbwU? 3 2 1 2 – 3 2 1 2 3 2 – 1 2 – 3 2 – 1 2 DËi: – 3 2 1 2 e ̈vL ̈v: x = rcos = 1 cos150 = cos (2 90 – 30) = – cos30 = – 3 2 Ges y = rsin = 1.sin150 = sin(2 90 – 30) = sin30 = 1 2 Kv‡Z©mxq ̄’vbv1⁄4 (x, y) – 3 2 1 2 2. – 3 2 2 3 2 2 we›`ywUi †cvjvi ̄’vbvsK KZ? 3 7 4 3 5 4 3 3 4 3 4 DËi: 3 3 4 e ̈vL ̈v: r = – 3 2 2 2 + 3 2 2 2 = 18 4 + 18 4 = 36 4 = 3 = – tan–1 y x = – tan–1 3 2 2 –3 2 2 = – tan–1 1 = – 4 = 3 4 †cvjvi ̄’vbvsK 3 3 4 3. (– 2 – 2) we›`yi †cvjvi ̄’vbvsK †KvbwU? 2 – 3 2 2 3 2 2 – 5 4 2 5 4 DËi: 2 5 4 e ̈vL ̈v: r = x 2 + y2 = ( – 2) 2 + (– 2) 2 = 4 = 2 = + tan–1 y x = + tan–1 – 2 – 2 = + tan–1 1 = + 4 = 5 4 4. (1, – 1) we›`ywUi †cvjvi ̄’vbvsK †KvbwU? ( 2, 45) ( 2, 135) ( 2, 225) ( 2, 315) DËi: ( 2, 315) e ̈vL ̈v: r = (1) 2 + (–1) 2 = 2 = 2 – tan–1 y x = 2 – tan–1 –1 1 = 2 – tan–1 1 = 2 – 4 = 7 4 = 315 (r, ) = ( 2, 315) 5. ( 3, 1) we›`ywUi †cvjvi ̄’vbvsK †KvbwU? (2, 30) (2, 45) (2, 60) (2, 90) DËi: (2, 30) e ̈vL ̈v: r = ( 3) 2 + 12 = 4 = 2 = tan–1 y x = tan–1 1 3 = 30 (r, ) = (2, 30) 6. y 2 = 1 + 2x mgxKiYwUi †cvjvi mgxKiY †KvbwU? 2rcos2 = 1 2rsin2 = 1 2rcos2 2 = 1 2rsin2 2 = 1 DËi: 2rsin2 2 = 1 e ̈vL ̈v: y 2 = 1 + 2x x 2 + y2 = x 2 + 1 + 2x x 2 + 2x + 1 = x2 + y2 (x + 1)2 = x 2 + y2
2 Higher Math 1st Paper Chapter-3 r 2 = (1 + rcos) 2 r = 1 + rcos r – rcos = 1 r 1 – cos2 2 = 1 r 2 sin2 2 = 1 2rsin2 2 = 1 7. rcos(– ) = k mgxKiYwUi Kv‡Z©mxq mgxKiY †KvbwU? xcos + ysin = k xcos + ysin = k xcos – ysin = k xcos – ysin = k DËi: xcos + ysin = k e ̈vL ̈v: rcos( – ) = k rcos.cos + rsin sin= k xcos + ysin = k 8. †Kv‡bv we›`yi †cvjvi ̄’vbvsK (c, ) n‡j we›`ywUi Kv‡Z©mxq ̄’vbvsK KZ? [DU 21-22] (–1, 0) (– c, 0) (c, – c) (– c, c) DËi: (– c, 0) e ̈vL ̈v: x = rcos = c.cos = – c y = rsin = c.sin = 0 we›`ywU (– c, 0) x = y 9. r = a sin †cvjvi mgxKi‡Yi Kv‡Z©mxq mgxKiY KZ? ax 2 + y2 – y = 0 x 2 + y2 + ay = 0 x 2 + y2 – ay = 0 x 2 + ay2 – y = 0 DËi: x 2 + y2 – ay = 0 e ̈vL ̈v: r = asin r 2 = arsin [x2 + y2 = r2 , y = rsin] x 2 + y2 = ay x 2 + y2 – ay = 0 10. x A‡ÿi Ici Aew ̄’Z GKwU we›`y p n‡Z (1, 2) I (4, 5) we›`y `yBwUi `~iZ¡ mgvb n‡j p we›`yi ̄’vbvsK KZ? (0, 6) (0, 9) (6, 0) (9, 0) DËi: (6, 0) e ̈vL ̈v: g‡b Kwi, p we›`ywU (x, 0) kZ©g‡Z, (x – 1)2 + (0 – 2)2 = (x – 4)2 + (0 – 5)2 x 2 – 2x + 1 + 4 = x2 – 8x + 16 + 25 – 2x + 5 + 8x – 41 = 0 x = 6 p we›`yi ̄’vbvsK (6, 0) 11. y Aÿ I (7, 2) †_‡K (a, 5) we›`ywUi `~iZ¡ mgvb n‡j, a Gi gvb KZ? 29 7 29 9 27 7 29 5 DËi: 29 7 e ̈vL ̈v: y Aÿ †_‡K (a, 5) we›`yi `~iZ¡ = |a| Ges (7, 2) n‡Z (a, 5) Gi `~iZ¡ = (7 – a) 2 + (2 – 5) 2 = 7 2 – 2.7a + a2 + (–3) 2 = a 2 – 14a + 58 kZ©g‡Z, a 2 – 14a + 58 = |a| a 2 – 14a + 58 = a2 14a = 58 a = 58 14 = 29 7 12. †Kv‡bv we›`yi †KvwU 3 Ges we›`ywUi `~iZ¡ (5, 3) †_‡K 4 GKK n‡j we›`ywUi fzR KZ? 3 A_ev 9 2 A_ev 7 3 A_ev 5 9 A_ev 1 DËi: 9 A_ev 1 e ̈vL ̈v: †`Iqv Av‡Q, we›`yi †KvwU 3| awi fzR p we›`ywUi ̄’vbvsK (p, 3) (p, 3) n‡Z (5, 3) we›`ywUi `~iZ¡ = (p – 5) 2 + (3 – 3) 2 kZ©g‡Z, (p – 5) 2 + (3 – 3) 2 = 4 p 2 – 10p + 25 – 16 = 0 p 2 – 10p + 9 = 0 p 2 – 9p – p + 9 = 0 p(p – 9) – 1(p – 9) = 0 (p – 9) (p – 1) = 0 p = 9 or p = 1 13. `ywU we›`yi †cvjvi ̄’vbvsK (2 3 , 90) Ges (2 5, 180) n‡j we›`y `ywUi `~iZ¡ KZ? 4 3 4 2 4 5 2 3 0 DËi: 4 2 e ̈vL ̈v: Avgiv Rvwb, `ywU †cvjvi we›`yi ga ̈eZ©x `~iZ¡, = r1 2 + r2 2 – 2r1r2 cos(1 – 2) (2 3, 90) Ges (2 5, 180) Gi ga ̈eZ©x `~iZ¡, = (2 3) 2 + (2 5) 2 – 2.2 3.2 5 cos(180– 90) = 12 + 20 – 0 = 32 = 16 2 = 4 2 14. GKwU mgevû wÎfz‡Ri `ywU kxl©we›`yi ̄’vbvsK (2, 1) Ges (2, 5) n‡j, Z...Zxq kxl©we›`yi ̄’vbvsK KZ? (2 + 2 3, 3) (2 + 3, 3) (3 + 2 3, 3) (3 + 3, 3) DËi: (2 + 2 3, 3)