Question

Cine ma ajuta? Va rog!

Answer 1

$x^{2} - \sqrt{5}x+1=0 \\ \\ a=1 \\ \\ b=- \sqrt{5} \\ \\ c=1 \\ \\ \Delta =b^2-4ac=(- \sqrt{5})^2-4 \cdot 1 \cdot1=5-4=1. \\ \\ x_{1,2}= \frac{-b \pm \sqrt{\Delta}}{2a}= \frac{\sqrt{5} \pm 1}{2}. \\ \\ \underline{Solutie}:~x \in \Big \{ \frac{ \sqrt{5}-1}{2}; \frac{ \sqrt{5}+1}{2} \Big \}.$