Question

calculate if x+1/x=-1 then find the value of x³-1​

Answer 1

here (x+ 1/x) = -1

=> (x^2 + 1) = -x

=> x^2 + x + 1 = 0

now ,

apply The formula (a^3 - b^3) = (a - b)(a^2+ab+b^2)

we get,

x³-1

= (x - 1)(x^2 + x.1 + 1^2)

= (x - 1) (0). { put the value x^2 + x + 1 = 0 }

= 0

the value of x³-1 = 0