Ratsionaalarvud

II. Hulk ja selle osahulk.

1) Eralda hulgast Y = {1; 2; 3; 4; 5; 6; 7; 8; 10; 12} välja kõik sellised mittetühjad osahulgad, mille korral võrratus on tõene. Näiteks kui x < 3, siis on vastavad osahulgad {1}, {2} ja {1; 2}.

a) x < 7    ........................................................................................................

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b) x > 10      ......................................................................................................

c) 4 < x < 7   .....................................................................................................

d) 10 < x < 12   .................................................................................................

e) 1 < x < 5 .....................................................................................................

f) 8 < x < 12   ....................................................................................................

2) Eralda hulgast S = {0,25; 1; 4; 9; 16; 25; 36} välja kõik sellised mittetühjad osahulgad, mille elementide kohta kehtib antud väide. Näiteks ainult ühekohalisi arve sisaldavad osahulgad on {1}, {4}, {9}, {1; 4}, {4; 9}, {1; 9} ja {1; 4; 9}.

a) Osahulka kuuluvad ainult paarisarvud  .........................................................

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b) Osahulga kõik elemendid on mittetäisarvud  ..............................................

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c) Osahulka kuuluvad ainult 3-ga jaguvad arvud  ............................................

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d) Osahulga kõik elemendid on kahekohalised  ............................................

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e) Osahulga iga elemendi ruutjuur on suurem kui element ise  ....................

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