Korzystając z tablic trygonometrycznych dostajemy:

a) 

$3\cdot \mathrm{tg}{17}^{\circ }\approx 3\cdot 0,306=0,918\approx 0,92$

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b)

$2\cdot \sin {52}^{\circ }+3\approx 2\cdot 0,788+3=4,576\approx 4,58$

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c) 

$5-4\cos {27}^{\circ }\approx 5-4\cdot 0,891=1,436\approx 1,44$

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d)

$\mathrm{tg}{10}^{\circ }+\mathrm{tg}{80}^{\circ }\approx 0,176+5,671=5,847\approx 5,85$

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e)

$3\cdot \sin {76}^{\circ }+2\cdot \cos {18}^{\circ }\approx 3\cdot 0,970+2\cdot 0,951=2,91+1,902=4,812\approx 4,81$

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f)

$5\cdot \mathrm{tg}{67}^{\circ }-12\cos {85}^{\circ }\approx 5\cdot 2,3559-12\cdot 0,0872=11,7795-1,0464=10,7331\approx 10,73$

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g)

$1-{\sin }^2{75}^{\circ }\approx 1-{0,966}^2=1-0,933156=0,066844\approx 0,07$

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h)

${\mathrm{tg}}^2{50}^{\circ }+{\mathrm{tg}}^2{40}^{\circ }\approx {1,192}^2+{0,839}^{\circ }=1,420864+0,703921=2,124785\approx 2,12$  

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i) 

${\cos }^2{17}^{\circ }-{\sin }^2{71}^{\circ }\approx {0,956}^2-{0,946}^2=0,913936-0,894916=0,01902\approx 0,02$