Se dau numerele : a=√128 •(1/√8-1/√32) si b=√2 + 1-√2/2-√2.Calculati a•b-√2


Răspuns :

[tex]a = \sqrt{128} \times ( \frac{1}{ \sqrt{8} } - \frac{1}{ \sqrt{32} } )[/tex]

[tex]a = 8 \sqrt{2} \times ( \frac{1}{2 \sqrt{2} } - \frac{1}{4 \sqrt{2} } )[/tex]

[tex]a = \frac{8 \sqrt{2} }{2 \sqrt{2} } - \frac{8 \sqrt{2} }{4 \sqrt{2} } [/tex]

[tex]a = 4 - 2[/tex]

[tex]a = 2[/tex]

[tex]b = \sqrt{2} + 1 - \frac{ \sqrt{2} }{2} - \sqrt{2} [/tex]

[tex]b = 1 - \frac{ \sqrt{2} }{2} [/tex]

[tex]b = \frac{2 - \sqrt{2} }{2} [/tex]

[tex]ab - \sqrt{2} = 2 \times \frac{2 - \sqrt{2} }{2} - \sqrt{2} = 2 - \sqrt{2} - \sqrt{2} = 2 - 2 \sqrt{2} = 2(1 - \sqrt{2} )[/tex]