If ` alpha and beta` are the roots of the equation `x^(2) - 2x + 4 = 0` , then what is the value of ` alpha^(3) + beta^(3)` ?

If alpha and beta are the roots of the equation 4x^(2) + 3x + 7 = 0 , then what is the value of (alpha^(-2) + beta^(-2)) ?

If alpha,beta " are the roots of the equation "x^(2) - 2x - 1 =0, "then what is the value of " alpha^(2)beta^(-2)+alpha^(-2)beta^(2)

If alpha and beta are the roots of the equations x^(2)-2x-1=0 , then what is the value of alpha^(2)beta^(-2)+beta^(2)alpha^(-2)