Question

If x^2 + 1/x^2 = 1, then the value of x^3+1/x^3 is :
a.3
b.1
c. root 3
d.0
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Answer 1

(x+1/x)²=x²+1/x²+2×x×1/x=x²+1/x²+2

=1+2=3

x+1/x=√3

(x+1/x)³=x³+1/x³+3(x+1/x)

(√3)³=x³+1/x³+3(√3)

x³+1/x³=(√3)³-3√3=3√3-3√3=0