Odpowiedź:
[tex]a)\ \ w(x)=x^2+4x-9\\\\w(2)=2^2+4\cdot2-9=4+8-9=12-9=3\\\\w(-\frac{1}{4})=(-\frac{1}{4})^2+4\cdot\frac{1}{4}-9=\frac{1}{16}+1-9=\frac{1}{16}-8=\frac{1}{16}-7\frac{16}{16}=-7\frac{15}{16}\\\\\\b)\ \ w(x)=x^4+3x^3-x^2-6x+8\\\\w(-\sqrt{2})=(-\sqrt{2})^4+3\cdot(-\sqrt{2})^3-(-\sqrt{2})^2-6\cdot(-\sqrt{2})+8=\\\\=(\sqrt{2})^4+3\cdot(-\sqrt{8})-2+6\sqrt{2}+8=\sqrt{16}-3\sqrt{8}+6\sqrt{2}+6=4-3\sqrt{4\cdot2}+6\sqrt{2}+6=\\\\=10-3\cdot2\sqrt{2}+6\sqrt{2}=10-6\sqrt{2}+6\sqrt{2}=10[/tex]
