Question

If X = 5-√21/2 prove that (x^3+1/x^3) -5 (x^2+1/x^2) +(X+1/X)= 0​

Answer 1

Answer:

ans is 0

Step-by-step explanation:

X=(5-√21)/2

1/x=2/(5-√21)=2(5+√21)/4=(5+√21)/2

now,

x+1/x=5

x^2+1/x^2=5^2-2=23

x^3+1/x^3=5^3-3*5=110

putting values

110-5*23+5=0

hope it will help you

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