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- .SET #8(*5, *)
- .LET (*#34=#34+#8*) TEXT
- .LET (*#25=#25+#6*)
- @LAB:SCREEN52
- .SCR 2
- .SNA(*(.INF 39)2*)
- .LOC 2,46(*52*)
- .LOC 5,11(*Problems on the Parabola*)
- .DRA(*BM72,28C1R207D15L207U15*)
- .PAU(**) #4
- .LOC 8,11(*Here are some typical problems which you will meet.*)
- .PAU(**) #4
- .LOC 10,11(*There are some important points made during the solution of*)
- .LOC 12,11(*these sample problems which you should note most carefully.*)
- .SPE PLAY (*AM050424.SPE*) WAIT
- .PAU(**) #4
- .LOC 15,15(*If the parameter of one end of a focal chord of the*)
- .LOC 17,15(*parabola y² = 4ax is p and of the other end is q,*)
- .LOC 19,23(*find a relationship between p and q.*)
- .PAU(**) #4
- .USE PROG=PAUSE.USE
- .WIP (4,2)-(23,79) #11
- .LOC 2,46(*52a*)
- .LOC 10,40(*The points will be (ap²,2ap)*)
- .LOC 12,40(*and (aq²,2aq).*)
- .PUT 60,70 PART=30
- .LOC 14,40(*Since PQ passes through S, the*)
- .LOC 16,40(*gradient PS = gradient QS*)
- .SPE PLAY (*AM050425.SPE*) WAIT
- .PAU(**) #4
- .LOC 20,11(*Slope PS =*)
- .LOC 19,22(*2ap - 0*)
- .LOC 21,22(*ap² - a*)
- .DRA (*C1BM167,156M222,156*)
- .PAU(**) #4
- .LOC 20,30(*=*)
- .LOC 19,34(*2p*)
- .LOC 21,32(*p² - 1*)
- .DRA (*C1BM247,156M292,156*)
- .PAU(**) #4
- .LOC 20,43(*Slope QS =*)
- .LOC 19,54(*2aq - 0*)
- .LOC 21,54(*aq² - a*)
- .DRA (*C1BM423,156M479,156*)
- .PAU(**) #4
- .LOC 20,62(*=*)
- .LOC 19,66(*2q*)
- .LOC 21,64(*q² - 1*)
- .DRA (*C1BM503,156M548,156*)
- .PAU(**) #4
- .USE PROG=PAUSE.USE
- .WIP (4,2)-(23,79) #12
- .LOC 2,46(*52b*)
- .LOC 12,11(*These are equal:*)
- .PAU(**) #4
- .LOC 11,37(*2p*)
- .LOC 13,35(*p² - 1*)
- .DRA (*C1BM271,92M316,92*)
- .LOC 12,43(*=*)
- .LOC 11,48(*2q*)
- .LOC 13,46(*q² - 1*)
- .DRA (*C1BM360,92M404,92*)
- .PAU(**) #4
- .LOC 15,11(*Divide by 2 and clear the denominators:*)
- .PAU(**) #4
- .LOC 17,32(*p(q² - 1) = q(p² - 1)*)
- .PAU(**) #4
- .LOC 19,26(*»*)
- .LOC 19,34(*pq² - p = qp² - q*)
- .PAU(**) #4
- .LOC 21,11(*Re-arrange:*)
- .PAU(**) #4
- .LOC 21,32(*pq² - qp² = p - q*)
- .PAU(**) #4
- .USE PROG=PAUSE.USE
- .WIP (4,2)-(23,79) #8
- .LOC 2,46(*52c*)
- .LOC 15,20(*»*)
- .LOC 15,32(*pq(q - p) = (p - q)*)
- .PAU(**) #4
- .LOC 17,12(*Since p and q are distinct points, q - p is not equal to 0*)
- .LOC 19,10(*so we may divide through by it and remember, p - q = - (q - p)*)
- .PAU(**) #4
- .LOC 21,20(*»*)
- .LOC 21,39(*pq = - 1*)
- .DRA (*C1BM304,169M373,169*)
- .SPE PLAY (*AM050426.SPE*) WAIT
- .PUT 500,187 PART=2 PSET
- @SIN(*"C"=L:SCREEN53,"c"=L:SCREEN53,"R"=L:-SCREEN52,"r"=L:-SCREEN52*)
- @LAB:SCREEN53
- .SNA(*(.INF 39)2*)
- .LOC 2,46(*53*)
- .LOC 5,11(*Another example...*)
- .PAU(**) #4
- .WIP (4,2)-(23,79)
- .LOC 5,15(*Find the equation of any chord joining 2 points on the*)
- .LOC 7,18(*parabola y² = 4ax with parameters p and q.*)
- .USE PROG=PAUSE.USE
- .LOC 9,40(*Points are (ap²,2ap) and (aq²,2aq)*)
- .PUT 60,70 PART=31
- .PAU(**) #4
- .LOC 12,40(*Gradient PQ =*)
- .LOC 11,55(*2ap - 2aq*)
- .LOC 13,55(*ap² - aq²*)
- .DRA (*C1BM432,92M501,92*)
- .PAU(**) #4
- .LOC 16,52(*=*)
- .LOC 15,54(*2a(p - q)*)
- .LOC 17,54(*a(p² - q²)*)
- .DRA (*C1BM423,124M500,124*)
- .PAU(**) #4
- .LOC 19,11(*P and Q are distinct points*)
- .PAU(**) #4
- .LOC 19,40(*» p*)
- .PUT 352,144 PART=41
- .LOC 19,47(*q*)
- .PAU(**) #4
- .LOC 19,51(*» p - q*)
- .PUT 480,144 PART=41
- .LOC 19,63(*0*)
- .SPE PLAY (*AM050427.SPE*) WAIT
- .PAU(**) #4
- .LOC 21,17(*and remember p² - q² ≡ (p - q)(p + q)*)
- .USE PROG=PAUSE.USE
- .WIP (4,2)-(23,79) #10
- .LOC 2,46(*53a*)
- .LOC 14,23(*Gradient PQ =*)
- .LOC 13,39(*2a(p - q)*)
- .LOC 15,39(*a(p² - q²)*)
- .DRA (*C1BM304,108M379,108*)
- .LOC 14,51(*=*)
- .LOC 13,56(*2*)
- .LOC 15,54(*p + q*)
- .LOC 14,54(*─────*)
- .PAU(**) #4
- .LOC 18,15(*Chord is:*)
- .PAU(**) #4
- .LOC 18,39(*y - 2ap =*)
- .LOC 17,53(*2*)
- .LOC 19,51(*p + q*)
- .LOC 18,51(*─────.(x - ap²)*)
- .PAU(**) #4
- .LOC 21,25(*y(p + q) - 2ap(p + q) = 2x - 2ap²*)
- .PAU(**) #4
- .USE PROG=PAUSE.USE
- .WIP (4,2)-(23,79) #7
- .LOC 2,46(*53b*)
- .LOC 16,23(*y(p + q) - 2x - 2ap² - 2apq + 2ap² = 0*)
- .PAU(**) #4
- .LOC 18,26(*y(p + q) - 2x - 2apq = 0*)
- .PAU(**) #4
- .LOC 21,26(*2x - (p + q)y + 2apq = 0*)
- .DRA(*BM191,156C1R226D15L226U15*)
- .SPE PLAY (*AM050428.SPE*) WAIT
- .PUT 500,187 PART=2 PSET
- @SIN(*"C"=L:SCREEN54,"c"=L:SCREEN54,"R"=L:-SCREEN53,"r"=L:-SCREEN53*)
- @LAB:SCREEN54
- .SNA(*(.INF 39)2*)
- .LOC 2,46(*54*)
- .LOC 5,11(*Another example...*)
- .PAU(**) #4
- .WIP (4,2)-(23,79)
- .LOC 5,15(*Find the locus of the points of intersection of the*)
- .LOC 7,9(*tangents from each end of a focal chord of the parabola y² = 4ax*)
- .USE PROG=PAUSE.USE
- .PUT 60,70 PART=32
- .PAU(**) #4
- .LOC 10,40(*Let P be (ap²,2ap) and Q be*)
- .LOC 12,40(*(aq²,2aq).*)
- .PAU(**) #4
- .LOC 12,53(*Use ty - x = at²*)
- .PAU(**) #4
- .LOC 14,40(*Tangent at P:*)
- .PAU(**) #4
- .LOC 14,58(*py - x = ap²*)
- .PAU(**) #4
- .LOC 16,40(*Tangent at Q:*)
- .PAU(**) #4
- .LOC 16,58(*qy - x = aq²*)
- .PAU(**) #4
- .LOC 18,40(*Subtract:*)
- .PAU(**) #4
- .DRA (*C1BM448,132M591,132*)
- .LOC 18,57(*py - qy = ap² - aq²*)
- .PAU(**) #4
- .LOC 20,48(*»*)
- .LOC 20,56(*y(p - q) = a(p² - q²)*)
- .PAU(**) #4
- .USE PROG=PAUSE.USE
- .WIP (4,2)-(23,79) #15
- .LOC 2,46(*54a*)
- .LOC 7,15(*Since P and Q are distinct points, p*)
- .PUT 416,48 PART=41
- .LOC 7,55(*q*)
- .PAU(**) #4
- .LOC 7,58(*» p - q*)
- .PUT 528,48 PART=41
- .LOC 7,69(*0*)
- .PAU(**) #4
- .LOC 9,23(*and remember that p² - q² ≡ (p - q)(p + q)*)
- .SPE PLAY (*AM050429.SPE*) WAIT
- .PAU(**) #4
- .LOC 11,48(*»*)
- .LOC 11,62(*y = a(p + q)*)
- .PAU(**) #4
- .LOC 13,15(*Substitute back in the tangent at P:*)
- .PAU(**) #4
- .LOC 15,33(*a(p + q).p - x = ap²*)
- .PAU(**) #4
- .LOC 17,22(*»*)
- .LOC 17,46(*x = ap² + apq - ap²*)
- .PAU(**) #4
- .LOC 17,68(*= apq*)
- .PAU(**) #4
- .LOC 19,22(*»*)
- .LOC 19,28(*T is at ( apq , a(p + q) )*)
- .PAU(**) #4
- .LOC 21,11(*But PQ is a focal chord, for which we found earlier pq = - 1*)
- .SPE PLAY (*AM050430.SPE*) WAIT
- .PAU(**) #4
- .USE PROG=PAUSE.USE
- .WIP (4,2)-(23,79) #14
- .LOC 2,46(*54b*)
- .LOC 9,22(*» T is at ( -a , a(p + q) )*)
- .PAU(**) #4
- .LOC 11,15(*for which x never varies and is always equal to - a*)
- .SPE PLAY (*AM050431.SPE*) WAIT
- .PAU(**) #4
- .LOC 13,22(*»*)
- .LOC 13,27(*T lies on the line x = - a [ the directrix ]*)
- .DRA (*C1BM208,104M423,104*)
- .USE PROG=PAUSE.USE
- .LOC 16,12(*It is also an interesting point in this particular example*)
- .LOC 18,11(*that the gradient of the tangent at P is*)
- .PUT 408,134 PART=33
- .LOC 18,55(*and that of the*)
- .LOC 20,12(*tangent at Q is*)
- .PUT 216,150 PART=34
- .PAU(**) #4
- .LOC 20,31(*and since*)
- .PUT 336,150 PART=33
- .LOC 20,45(*x*)
- .PUT 368,150 PART=34
- .LOC 20,50(*=*)
- .PUT 416,150 PART=42
- .LOC 20,56(*=*)
- .PUT 460,150 PART=35
- .LOC 20,61(*= - 1*)
- .PAU(**) #4
- .LOC 22,22(*»*)
- .LOC 22,28(*the tangents are perpendicular*)
- .PUT 500,187 PART=2 PSET
- @SIN(*"C"=L:SCREEN55,"c"=L:SCREEN55,"R"=L:-SCREEN54,"r"=L:-SCREEN54*)
- @LAB:SCREEN55
- .SNA(*(.INF 39)2*)
- .LOC 2,46(*55*)
- .LOC 5,15(*What is the point of contact of the tangent 2y = x + 16*)
- .LOC 7,27(*to the parabola y² = 16x ?*)
- .USE PROG=PAUSE.USE
- .LOC 10,15(*The equation of the tangent at the point with parameter*)
- .LOC 12,15(*t is given by ty - x = at²*)
- .PAU(**) #4
- .LOC 14,15(*Replace t by*)
- .PUT 240,102 PART=36
- .LOC 14,33(*:*)
- .PAU(**) #4
- .PUT 312,102 PART=37
- .LOC 14,43(*- x =*)
- .PUT 389,102 PART=38
- .PAU(**) #4
- .LOC 17,15(*Multiply through by m:*)
- .PAU(**) #4
- .LOC 17,40(*y - mx =*)
- .PUT 392,126 PART=39
- .PAU(**) #4
- .LOC 20,30(*»*)
- .LOC 20,39(*y = mx +*)
- .PUT 392,150 PART=39
- .DRA(*BM408,147C1L113D19R113U19*)
- .SPE PLAY (*AM050432.SPE*) WAIT
- .PAU(**) #4
- .USE PROG=PAUSE.USE
- .WIP (4,2)-(23,79) #14
- .LOC 2,46(*55a*)
- .LOC 9,11(*For ALL VALUES OF m,*)
- .PAU(**) #4
- .LOC 9,34(*y = mx +*)
- .PUT 336,62 PART=39
- .LOC 9,46(*is a tangent to the*)
- .LOC 11,11(*parabola y² = 4ax and it touches the parabola at the*)
- .LOC 13,11(*point*)
- .PUT 200,92 PART=44
- .LOC 13,28(*a.(*)
- .PUT 244,94 PART=36
- .LOC 13,33(*)² , 2a.*)
- .PUT 320,94 PART=36
- .PUT 336,92 PART=45
- .PAU(**) #4
- .LOC 13,47(*= (*)
- .PUT 416,92 PART=38
- .LOC 13,56(*,*)
- .PUT 452,90 PART=40
- .LOC 13,60(*)*)
- .DRA (*C1BM402,108M476,108*)
- .PAU(**) #4
- .LOC 16,11(*We have 2y = x + 16*)
- .PAU(**) #4
- .LOC 16,39(*» y =*)
- .PUT 392,118 PART=43
- .LOC 16,53(*+ 8*)
- .PAU(**) #4
- .LOC 18,39(*» m =*)
- .PUT 392,134 PART=12
- .LOC 18,53(*and*)
- .PUT 456,134 PART=39
- .LOC 18,61(*= 8*)
- .PAU(**) #4
- .LOC 18,66(*» a = 4*)
- .PAU(**) #4
- .LOC 21,19(*Touches parabola at*)
- .PUT 320,156 PART=44
- .LOC 20,45(*4*)
- .LOC 21,43(*────*)
- .LOC 22,43(*(*)
- .PUT 344,166 PART=12
- .LOC 22,45(*)²*)
- .LOC 21,48(*,*)
- .LOC 20,50(*2.4*)
- .LOC 21,50(*───*)
- .PUT 400,166 PART=12
- .PUT 424,156 PART=45
- .PAU(**) #4
- .LOC 21,57(*= ( 16 , 16 )*)
- .DRA (*C1BM481,169M567,169*)
- .PUT 500,187 PART=2 PSET
- @SIN(*"C"=L:SCREEN56,"c"=L:SCREEN56,"R"=L:-SCREEN55,"r"=L:-SCREEN55*)
- @LAB:SCREEN56
- .COL 0,0
- .SCR 1
- .SNA(*(.INF 39)1*)
- .COL 8
- .PAL 1
- .LOC 2,23(*56*)
- .LOC 7,5(*At this point in the full version*)
- .LOC 9,9(*of the program the user is*)
- .LOC 11,5(*requested to complete a worksheet*)
- .LOC 13,6(*for this section, entering the*)
- .LOC 15,7(*results via the keyboard onto*)
- .LOC 17,9(*the computer for checking.*)
- .PAU(**)#4
- .LOC 19,6(*Type C <enter> to continue.*)
- .SET #10(*SCREEN57*)
- .USE PROG=PRESSC.USE
- @LAB:SCREEN57
- .COL 0,0
- .SCR 1
- .SNA(*(.INF 39)1*)
- .COL 8
- .PAL 1
- .LOC 2,23(*57*)
- .LOC 6,4(*However, in this demonstration the*)
- .LOC 8,7(*results checking facility is*)
- .LOC 10,4(*unavailable, so you will continue to*)
- .LOC 12,6(*the next phase of the tutorial.*)
- .PAU(**)#4
- .LOC 18,6(*Type C <enter> to continue.*)
- .SET #10(*SCREEN58Z*)
- .USE PROG=PRESSC.USE
- @LAB:SCREEN58Z
- .WIP (20,2)-(23,39)
- .PAU(**) #4
- .COL 1,
- .LOC 14,8(*Do you wish to:*)
- .COL 2,
- .LOC 16,4(*(C) continue to the next Part*)
- .LOC 18,4(*(R) return to the Contents page*)
- .COL 1,
- .LOC 20,8(*Please type C or R >*)
- .COL 3,
- @SIN (*"C"=C:AM0504G.CHA,"c"=C:AM0504G.CHA,"R"=L:BACKB,"r"=L:BACKB*)
- @LAB:BACKB
- @GOB:SCREEN09 PROG=AM0504
-
-