Question

область визначення
$y = x \sqrt{2 - x {}^{2} }$
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Answer 1

$y = x \sqrt{2 - {x}^{2} } \\ 2 - {x}^{2} \geqslant 0 \: \: | \times ( - 1) \\ {x}^{2} - 2 \leqslant 0 \\ (x - \sqrt{2} )(x + \sqrt{2} ) \leqslant 0 \\ + + + [ - \sqrt{2} ] - - - [ \sqrt{2} ] + + + \\ x \: \epsilon \: [ - \sqrt{2} ; \: \sqrt{2} ]$