Respuesta :

9514 1404 393

Answer:

  1/x = (1+√5)/2 ≈ 1.618034

Step-by-step explanation:

Since you are only interested in the second part, we presume you have solved the quadratic equation to find ...

  x = (√5 -1)/2 ≈ 0.618034

The second part asks for 1/x. The usual method for rationalizing the denominator will be useful for this. Multiply numerator and denominator by the conjugate of the denominator.

  [tex]\dfrac{1}{x}=1\div\dfrac{\sqrt{5}-1}{2}=1\times\dfrac{2}{\sqrt{5}-1}\\\\=\dfrac{2(\sqrt{5}+1)}{(\sqrt{5}-1)(\sqrt{5}+1)}=\dfrac{2\sqrt{5}+2}{5-1}=\boxed{\dfrac{\sqrt{5}+1}{2}\approx1.618034}[/tex]

_____

Additional comment

You may notice that 1/x = x+1.