Question

if x= 1%root 5-2, than find the value of x^2+1%x^2​

Answer 1

Answer:

x=

5

−2

1

x = \frac{1( \sqrt{5} + 2) }{( \sqrt{5} - 2)( \sqrt{5} + 2) }x=

(

5

−2)(

5

+2)

1(

5

+2)

x = \frac{ \sqrt{5} - 2 }{ { (\sqrt{5} }^{2}) - {2}^{2} }x=

(

5

2

)−2

2

5

−2

x=√5-2

1/x=√5+2

(x+1/x)=2√5

(x+1/x)²=(2√5)²

x²+1/x²+2(x)(1/x)=20

x²+1/x²+2=20

x²+1/x²=18