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12.2E: Mazoezi ya Sehemu ya 12.2

  • Page ID
    178085
    • Edwin “Jed” Herman & Gilbert Strang
    • OpenStax
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    1) Fikiria sanduku la mstatili na moja ya alama za asili, kama inavyoonekana katika takwimu ifuatayo. Ikiwa hatua\(A(2,3,5)\) ni vertex kinyume na asili, kisha tafuta

    a. kuratibu za vipeo vingine sita vya sanduku na

    b. urefu wa diagonal ya sanduku iliyowekwa na vertices\(O\) na\(A\).

    Jibu
    a.\((2,0,5),(2,0,0),(2,3,0),(0,3,0),(0,3,5),(0,0,5)\) b.\(\sqrt{38}\)

    2) Pata kuratibu za uhakika\(P\) na ueleze umbali wake na asili.

    Kwa mazoezi 3-6, kuelezea na grafu seti ya pointi ambazo zinatimiza equation iliyotolewa.

    3)\((y−5)(z−6)=0\)

    Jibu
    Muungano wa ndege mbili:\(y=5\) (ndege sambamba na\(xz\) -ndege) na\(z=6\) (ndege sambamba na\(xy\) -ndege)

    4)\((z−2)(z−5)=0\)

    5)\((y−1)^2+(z−1)^2=1\)

    Jibu
    Silinda ya radius\(1\) iliyozingatia mstari\(y=1,z=1\)

    6)\((x−2)^2+(z−5)^2=4\)

    7) Andika equation ya ndege inayopitia hatua\((1,1,1)\) ambayo ni sawa na\(xy\) -ndege.

    Jibu
    \(z=1\)

    8) Andika equation ya ndege inayopitia hatua\((1,−3,2)\) ambayo ni sawa na\(xz\) -ndege.

    9) Pata usawa wa ndege inayopitia pointi\((1,−3,−2), (0,3,−2),\) na\((1,0,−2).\)

    Jibu
    \(z=−2\)

    10) Pata usawa wa ndege inayopitia pointi\((1,9,2), (1,3,6),\) na\((1,−7,8).\)

    Kwa mazoezi 11-14, pata usawa wa nyanja kwa fomu ya kawaida ambayo inatimiza masharti yaliyotolewa.

    11) Kituo\(C(−1,7,4)\) na radius\(4\)

    Jibu
    \((x+1)^2+(y−7)^2+(z−4)^2=16\)

    12) Kituo\(C(−4,7,2)\) na radius\(6\)

    13) Kipenyo\(PQ,\) wapi\(P(−1,5,7)\) na\(Q(−5,2,9)\)

    Jibu
    \(x+3)^2+(y−3.5)^2+(z−8)^2=\dfrac{29}{4}\)

    14) Kipenyo\(PQ,\) wapi\(P(−16,−3,9)\) na\(Q(−2,3,5)\)

    Kwa mazoezi 15 na 16, tafuta kituo na radius ya nyanja na equation kwa fomu ya jumla inayotolewa.

    15)\( x^2+y^2+z^2−4z+3=0\)

    Jibu
    Kituo\(C(0,0,2)\) na radius\(1\)

    16)\(x^2+y^2+z^2−6x+8y−10z+25=0\)

    Kwa mazoezi 17-20, onyesha vector\( \vecd{PQ} \) na hatua ya awali\(P\) na hatua ya mwisho\(Q\)

    \(a.\)katika fomu ya sehemu na

    \(b.\)kwa kutumia kiwango kitengo wadudu.

    17)\(P(3,0,2)\) na\(Q(−1,−1,4)\)

    Jibu
    \(a. \vecd{PQ}=⟨−4,−1,2⟩\)
    \(b. \vecd{PQ}=−4\hat{\mathbf i}−\hat{\mathbf j}+2\hat{\mathbf k}\)

    18)\(P(0,10,5)\) na\(Q(1,1,−3)\)

    19)\(P(−2,5,−8)\) na\(M(1,−7,4)\),\(M\) wapi midpoint ya sehemu ya mstari\(\overline{PQ}\)

    Jibu
    \(a. \vecd{PQ}=⟨6,−24,24⟩\)
    \(b. \vecd{PQ}=6\hat{\mathbf i}−24\hat{\mathbf j}+24\hat{\mathbf k}\)

    20)\(Q(0,7,−6)\) na\(M(−1,3,2)\),\(M\) wapi midpoint ya sehemu ya mstari\(\overline{PQ}\)

    21) Pata hatua\(Q\) ya mwisho ya vector\(\vecd{PQ}=⟨7,−1,3⟩\) na hatua ya awali\(P(−2,3,5).\)

    Jibu
    \(Q(5,2,8)\)

    22) Pata hatua\(P\) ya awali ya vector\(\vecd{PQ}=⟨−9,1,2⟩\) na hatua ya mwisho\(Q(10,0,−1).\)

    Kwa mazoezi 23-26, tumia vectors zilizopewa\(\vecs a\) na\(\vecs b\) kupata na kuelezea vectors\(\vecs a+\vecs b, \,4\vecs a\), na\(−5\vecs a+3\vecs b\) katika fomu ya sehemu.

    23)\(\quad \vecs a=⟨−1,−2,4⟩,\quad \vecs b=⟨−5,6,−7⟩\)

    Jibu
    \(\vecs a+\vecs b=⟨−6,4,−3⟩, 4\vecs a=⟨−4,−8,16⟩, −5\vecs a+3\vecs b=⟨−10,28,−41⟩\)

    24)\(\quad \vecs a=⟨3,−2,4⟩,\quad \vecs b=⟨−5,6,−9⟩\)

    25)\(\quad \vecs a=−\hat{\mathbf k},\quad \vecs b=−\hat{\mathbf i}\)

    Jibu
    \(\vecs a+\vecs b=⟨−1,0,−1⟩, 4\vecs a=⟨0,0,−4⟩, −5\vecs a+3\vecs b=⟨−3,0,5⟩\)

    26)\(\quad \vecs a=\hat{\mathbf i}+\hat{\mathbf j}+\hat{\mathbf k},\quad \vecs b=2\hat{\mathbf i}−3\hat{\mathbf j}+2\hat{\mathbf k}\)

    Kwa mazoezi 27-30, vectors\(\vecs u\) na\(\vecs v\) hutolewa. Pata ukubwa wa vectors\(\vecs u−\vecs v\) na\(−2\vecs u\).

    27)\(\quad \vecs u=2\hat{\mathbf i}+3\hat{\mathbf j}+4\hat{\mathbf k}, \quad \vecs v=−\hat{\mathbf i}+5\hat{\mathbf j}−\hat{\mathbf k}\)

    Jibu
    \(\|\vecs u−\vecs v\|=\sqrt{38}, \quad \|−2\vecs u\|=2\sqrt{29}\)

    28)\(\quad \vecs u=\hat{\mathbf i}+\hat{\mathbf j}, \quad \vecs v=\hat{\mathbf j}−\hat{\mathbf k}\)

    29)\(\quad \vecs u=⟨2\cos t,−2\sin t,3⟩, \quad \vecs v=⟨0,0,3⟩,\quad\)\(t\) wapi idadi halisi.

    Jibu
    \(\|\vecs u−\vecs v\|=2, \quad \|−2\vecs u\|=2\sqrt{13}\)

    30)\(\quad \vecs u=⟨0,1,\sinh t⟩, \quad \vecs v=⟨1,1,0⟩,\quad\)\(t\) wapi idadi halisi.

    Kwa mazoezi 31-36, pata vector ya kitengo katika mwelekeo wa vector iliyotolewa\( \vecs a\) na ueleze kwa kutumia vector ya kawaida ya kitengo.

    31)\(\quad \vecs a=3\hat{\mathbf i}−4\hat{\mathbf j}\)

    Jibu
    \(\frac{3}{5}\hat{\mathbf i}−\frac{4}{5}\hat{\mathbf j}\)

    32)\(\quad \vecs a=⟨4,−3,6⟩\)

    33)\(\quad \vecs a=\vecd{PQ}\), wapi\( P(−2,3,1)\) na\(Q(0,−4,4)\)

    Jibu
    \(\frac{\sqrt{62}}{31}\hat{\mathbf i}−\frac{7\sqrt{62}}{62}\hat{\mathbf j}+\frac{3\sqrt{62}}{62}\hat{\mathbf k}\)

    34)\(\quad \vecs a=\vecd{OP},\) wapi\(P(−1,−1,1)\)

    35)\(\quad \vecs a=\vecs u−\vecs v+\vecs w,\) wapi\(\vecs u=\hat{\mathbf i}−\hat{\mathbf j}−\hat{\mathbf k},\quad \vecs v=2\hat{\mathbf i}−\hat{\mathbf j}+\hat{\mathbf k}, \quad\) na\(\vecs w=−\hat{\mathbf i}+\hat{\mathbf j}+3\hat{\mathbf k}\)

    Jibu
    \(−\frac{\sqrt{6}}{3}\hat{\mathbf i}+\frac{\sqrt{6}}{6}\hat{\mathbf j}+\frac{\sqrt{6}}{6}\hat{\mathbf k}\)

    36)\(\quad \vecs a=2\vecs u+\vecs v−\vecs w,\quad\) wapi\( \vecs u=\hat{\mathbf i}−\hat{\mathbf k}, \quad \vecs v=2\hat{\mathbf j} \quad\), na\( \vecs w=\hat{\mathbf i}−\hat{\mathbf j}\)

    37) Kuamua kama\(\vecd{AB}\) na\(\vecd{PQ}\) ni sawa vectors, wapi\(A(1,1,1),\,B(3,3,3),\,P(1,4,5),\) na\(Q(3,6,7).\)

    Jibu
    Vectors sawa

    38) Kuamua kama wadudu\(\vecd{AB}\) na\(\vecd{PQ}\) ni sawa, wapi\( A(1,4,1),\, B(−2,2,0),\, P(2,5,7),\) na\( Q(−3,2,1)\).

    Kwa mazoezi 39-42, pata vector\( \vecs u\) kwa ukubwa unaotolewa na hutimiza masharti yaliyotolewa.

    39)\(\quad \vecs v=⟨7,−1,3⟩, \, ‖\vecs u‖=10\),\(\vecs u\) na\(\vecs v\) kuwa na mwelekeo huo

    Jibu
    \(\vecs u=⟨\frac{70\sqrt{59}}{59},−\frac{10\sqrt{59}}{59},\frac{30\sqrt{59}}{59}⟩\)

    40)\(\quad \vecs v=⟨2,4,1⟩,\, ‖\vecs u‖=15\),\(\vecs u\) na\(\vecs v\) kuwa na mwelekeo huo

    41)\(\quad \vecs v=⟨2\sin t,\, 2\cos t,1⟩, ‖\vecs u‖=2,\vecs u\) na\(\vecs v\) uwe na maelekezo kinyume kwa yeyote\(t\),\(t\) wapi idadi halisi

    Jibu
    \(\vecs u=⟨−\frac{4\sqrt{5}}{5}\sin t,−\frac{4\sqrt{5}}{5}\cos t,−\frac{2\sqrt{5}}{5}⟩\)

    42)\(\quad \vecs v=⟨3\sinh t,0,3⟩,\, ‖\vecs u‖=5\),\(\vecs u\) na\(\vecs v\) kuwa na maelekezo kinyume kwa yoyote\(t\),\(t\) wapi idadi halisi

    43) Kuamua vector ya ukubwa\(5\) katika mwelekeo wa vector\(\vecd{AB}\), wapi\(A(2,1,5)\) na\(B(3,4,−7).\)

    Jibu
    \(⟨\frac{5\sqrt{154}}{154},\frac{15\sqrt{154}}{154},−\frac{30\sqrt{154}}{77}⟩\)

    44) Pata vector ya ukubwa\(2\) ambayo inaonyesha katika mwelekeo kinyume kuliko vector\(\vecd{AB}\), wapi\(A(−1,−1,1)\) na\(B(0,1,1).\) Kueleza jibu katika fomu ya sehemu.

    45) Fikiria pointi\(A(2,α,0), \, B(0,1,β),\) na\(C(1,1,β)\), wapi\(α\) na\(β\) ni namba halisi hasi. Kupata\(α\) na\(β\) vile kwamba\(\|\vecd{OA}−\vecd{OB}+\vecd{OC}\|=\|\vecd{OB}\|=4.\)

    Jibu
    \(α=−\sqrt{7}, \,β=−\sqrt{15}\)

    46) Fikiria pointi\(A(α,0,0),\,B(0,β,0),\) na\(C(α,β,β),\) wapi\(α\) na\(β\) ni chanya idadi halisi. Kupata\(α\) na\(β\) vile kwamba\(\|\overline{OA}+\overline{OB}\|=\sqrt{2}\) na\(\|\overline{OC}\|=\sqrt{3}\).

    47) Hebu\(P(x,y,z)\) kuwa hatua iko katika umbali sawa kutoka pointi\(A(1,−1,0)\) na\(B(−1,2,1)\). Onyesha hatua hiyo\(P\) iko juu ya ndege ya equation\(−2x+3y+z=2.\)

    48) Hebu\(P(x,y,z)\) kuwa hatua iko katika umbali sawa kutoka asili na uhakika\(A(4,1,2)\). Onyesha kwamba kuratibu ya uhakika P kukidhi equation\(8x+2y+4z=21.\)

    49) pointi\(A,B,\) na\(C\) ni collinear (katika utaratibu huu) kama uhusiano\({\|\vecd{AB}\|+\|\vecd{BC}\|=\|\vecd{AC}\|}\) ni kuridhika. Onyesha kwamba\(A(5,3,−1),\, B(−5,−3,1),\) na\(C(−15,−9,3)\) ni pointi collinear.

    50) Onyesha kwamba pointi\(A(1,0,1), \, B(0,1,1),\) na\(C(1,1,1)\) si collinear.

    51) [T] nguvu\(\vecs F\) ya\(50 \,N\) vitendo juu ya chembe katika mwelekeo wa vector\(\vecd{OP}\), ambapo\(P(3,4,0).\)

    Eleza nguvu kama vector katika fomu ya sehemu.

    pata angle kati ya nguvu\(\vecs F\) na mwelekeo mzuri wa\(x\) -axis. Eleza jibu kwa digrii zilizozunguka kwa integer iliyo karibu.

    Jibu
    \(a. \vecs F=⟨30,40,0⟩; \quad b. 53°\)

    52) [T] nguvu\(\vecs F\) ya\(40\,N\) vitendo juu ya sanduku katika mwelekeo wa vector\(\vecd{OP}\), ambapo\(P(1,0,2).\)

    Express nguvu kama vector kwa kutumia kiwango kitengo wadudu.

    pata angle kati ya nguvu\(\vecs F\) na mwelekeo mzuri wa\(x\) -axis.

    53) Ikiwa\(\vecs F\) ni nguvu inayohamisha kitu kutoka hatua\(P_1(x_1,y_1,z_1)\) hadi hatua nyingine\(P_2(x_2,y_2,z_2)\), basi vector ya uhamisho hufafanuliwa kama\( \vecs D=(x_2−x_1)\hat{\mathbf i}+(y_2−y_1)\hat{\mathbf j}+(z_2−z_1)\hat{\mathbf k}\). Chombo cha chuma kinainuliwa\(10\) m kwa wima na nguvu ya mara kwa mara\(\vecs F\). Eleza vector ya uhamisho\(\vecs D\) kwa kutumia vectors ya kitengo cha kawaida.

    Jibu
    \(\vecs D=10\hat{\mathbf k}\)

    54) sanduku ni vunjwa\(4\) yd sambamba katika\(x\) -mwelekeo na nguvu ya mara kwa mara\( \vecs F\). Pata vector ya uhamisho katika fomu ya sehemu.

    55) Jumla ya nguvu zinazofanya kitu kinachojulikana kama nguvu au wavu. Kitu kinasemekana kuwa katika usawa wa tuli ikiwa nguvu ya matokeo ya nguvu zinazofanya juu yake ni sifuri. Hebu\(\vecs F_1=⟨10,6,3⟩, \vecs F_2=⟨0,4,9⟩\), na\(\vecs F_3=⟨10,−3,−9⟩\) uwe na vikosi vitatu vinavyofanya sanduku. Pata nguvu\(\vecs F_4\) inayofanya kwenye sanduku kama vile sanduku iko katika usawa wa tuli. Eleza jibu katika fomu ya sehemu.

    Jibu
    \(\vecs F_4=⟨−20,−7,−3⟩\)

    56) [T] Hebu\(\vecs F_k=⟨1,k,k^2⟩, k=1,...,n\) kuwa\(n\) vikosi vinavyofanya chembe, na\(n≥2.\)

    Kupata nguvu wavu\(\vecs F=\sum_{k=1}^n\vecs F_k.\) Express jibu kwa kutumia kiwango kitengo wadudu.

    b Tumia mfumo wa algebra ya kompyuta (CAS) ili kupata\(n\) vile\(\|\vecs F\|<100.\)

    57) Nguvu ya mvuto\( \vecs F\) inayofanya kitu hutolewa na\( \vecs F=m\vecs g\), wapi\(m\) wingi wa kitu (kilichoonyeshwa kwa kilo) na\(\vecs g\) ni kuongeza kasi kutokana na mvuto, na\( \|\vecs g\|=9.8 \,N/kg.\) mpira wa disco 2-kg hutegemea mlolongo kutoka dari ya chumba.

    Pata nguvu ya mvuto\(\vecs F\) inayofanya mpira wa disco na kupata ukubwa wake.

    pata nguvu ya mvutano\(\vecs T\) katika mlolongo na ukubwa wake.

    Eleza majibu kwa kutumia vectors ya kawaida ya kitengo.

    Kielelezo 18: (mikopo: mabadiliko ya kazi na Kenneth Lu, Flickr)
    Jibu
    \(a. \vecs F=−19.6\hat{\mathbf k}, \quad \|\vecs F\|=19.6 \,N\)
    \(b. \vecs T=19.6\hat{\mathbf k}, \quad \|\vecs T\|=19.6 \,N\)

    58) Chandelier ya pendant ya kilo 5 imeundwa kama bakuli la alabaster linafanyika na minyororo minne ya urefu sawa, kama inavyoonekana katika takwimu ifuatayo.

    Pata ukubwa wa nguvu ya mvuto inayofanya chandelier.

    pata ukubwa wa nguvu za mvutano kwa kila minyororo minne (kudhani minyororo ni kimsingi wima).

    59) [T] Block 30 kg ya saruji imesimamishwa na nyaya tatu za urefu sawa ambazo zimefungwa kwenye pointi\(P(−2,0,0), Q(1,\sqrt{3},0),\) na\(R(1,−\sqrt{3},0)\). Mzigo iko kwenye\(S(0,0,−2\sqrt{3})\), kama inavyoonekana katika takwimu ifuatayo. Hebu\(\vecs F_1, \vecs F_2\), na\(\vecs F_3\) uwe nguvu za mvutano kutokana na mzigo katika nyaya\(RS,QS,\) na\(PS,\) kwa mtiririko huo.

    Pata nguvu ya mvuto\(\vecs F\) inayofanya juu ya saruji ambayo inalingana na jumla ya nguvu\(\vecs F_1+\vecs F_2+\vecs F_3\) za mvutano katika nyaya.

    b. kupata vikosi\(\vecs F_1, \vecs F_2,\) na\( \vecs F_3\). Eleza jibu katika fomu ya sehemu.

    Jibu
    \(\vecs F=−294\hat{\mathbf k}\)n;
    b.\(\vecs F_1=⟨−\frac{49\sqrt{3}}{3},49,−98⟩, \vecs F_2=⟨−\frac{49\sqrt{3}}{3},−49,−98⟩\), na\(\vecs F_3=⟨\frac{98\sqrt{3}}{3},0,−98⟩\) (kila sehemu inaelezwa katika newtons)

    60) Wachezaji wawili wa soka wanafanya mazoezi kwa ajili ya mchezo ujao. Mmoja wao anaendesha 10 m kutoka hatua A kwa uhakika B. kisha anarudi kushoto katika\(90°\) na anaendesha 10 m mpaka yeye kufikia uhakika C. kisha yeye mateke mpira kwa kasi ya 10 m/sec katika angle ya juu ya\(45°\) kwa teammate yake, ambaye iko katika hatua A. kuandika kasi ya mpira katika fomu sehemu.

    61) Hebu\(\vecs r(t)=⟨x(t),\, y(t), \, z(t)⟩\) kuwa vector msimamo wa chembe wakati\(t∈[0,T]\), wapi\(x,y,\) na\(z\) ni kazi laini juu ya\([0,T]\). Kasi ya papo hapo ya chembe kwa wakati\(t\) hufafanuliwa na vector\(\vecs v(t)=⟨x'(t), \, y'(t), \, z'(t)⟩\), na vipengele ambavyo ni derivatives kwa heshima\(t\), ya kazi\(x, y\), na\(z\), kwa mtiririko huo. Ukubwa\(∥\vecs v(t)∥\) wa vector ya kasi ya haraka huitwa kasi ya chembe kwa wakati\(t\). Vector\(\vecs a(t)=⟨x''(t), \, y''(t), \, z''(t)⟩\), pamoja na vipengele ambavyo ni derivatives ya pili kwa heshima\(t\), ya kazi\(x,y,\) na\(z\), kwa mtiririko huo, hutoa kasi ya chembe kwa wakati\(t\). Fikiria\(\vecs r(t)=⟨\cos t,\, \sin t, \, 2t⟩\) vector msimamo wa chembe wakati\(t∈[0,30],\) ambapo vipengele vya\(\vecs r\) vinaelezwa kwa sentimita na wakati huelezwa kwa sekunde.

    Kupata kasi instantaneous, kasi, na kuongeza kasi ya chembe baada ya pili ya kwanza. Pindisha jibu lako kwa maeneo mawili ya decimal.

    Kutumia CAS kutazama njia ya chembeo-yaani, seti ya pointi zote za kuratibu\((\cos t,\sin t,2t),\) ambapo\(t∈[0,30].\)

    Jibu
    \(a. \vecs v(1)=⟨−0.84,0.54,2⟩\)(kila sehemu inaonyeshwa kwa sentimita kwa pili);\(∥\vecs v(1)∥=2.24\) (imeelezwa kwa sentimita kwa pili);\(\vecs a(1)=⟨−0.54,−0.84,0⟩\) (kila sehemu iliyoelezwa kwa sentimita kwa mraba wa pili);

    \(b.\)

    62) [T] Hebu\(\vecs r(t)=⟨t,2t^2,4t^2⟩\) kuwa vector nafasi ya chembe kwa wakati\(t\) (kwa sekunde), ambapo\(t∈[0,10]\) (hapa vipengele vya\(\vecs r\) vinaelezwa kwa sentimita).

    Kupata kasi instantaneous, kasi, na kuongeza kasi ya chembe baada ya sekunde mbili za kwanza. Pindisha jibu lako kwa maeneo mawili ya decimal.

    b Matumizi CAS taswira ya njia ya chembe defined na pointi\((t, \, 2t^2, \, 4t^2),\) ambapo\(t∈[0, \, 60].\)