![Sad :(](./images/smilies/icon_sad.gif)
[tex](\sqrt[3]{2}+1)\sqrt[3]{\frac{1}{3}(\sqrt[3]{2}-1)}[/tex]
Trekker sammen
[tex](\sqrt[3]{2}+1)\frac{\sqrt[3]{(\sqrt[3]{2}-1)}}{\sqrt[3]{3}}\text{ }\rightarrow\text{ }\frac{(\sqrt[3]{2}+1)\sqrt[3]{(\sqrt[3]{2}-1)}}{\sqrt[3]{3}}[/tex]
No sliter jeg litt, kan jeg gjøre sånn:
[tex]\frac{\sqrt[3]{(\sqrt[3]{2}-1)(\sqrt[3]{2}+1)^3}}{\sqrt[3]{3}}\text{ }\rightarrow\text{ }\frac{\sqrt[3]{(\sqrt[3]{2}-1)(\sqrt[3]{2}+1)(\sqrt[3]{2}+1)(\sqrt[3]{2}+1)}}{\sqrt[3]{3}}\text{ }\rightarrow\text{ }\frac{\sqrt[3]{3+2\sqrt[3]{2}}}{\sqrt[3]{3}}[/tex]
Innfører x:
[tex]x^3=\frac{3+2\sqrt[3]{2}}{3}[/tex]
[tex]3x^3=3+2\sqrt[3]{2}[/tex]
Men dette kan vel ikke være lett å regne ut i hodet
![Shocked :shock:](./images/smilies/icon_eek.gif)
Hva er det jeg gjør feil?