jika x pangakat 1/2 + x pangkat -1/2=2 berapa x² +x pangkat -2

x^1/2 + x ^ -1/2=2
= x = 2
jadi,
x^2 + x^ -2=
=2^2 + 2^ -2
=4 + (-4)
= 0

x^1/2 + x^-1/2 = 2
(x^1/2 + x^-1/2)^2 = 2^2
(x^1/2)^2 + 2 . x^1/2 . x^-1/2 + (x^-1/2)^2 = 4
x + 2 + x^-1 = 4
x + x^-1 = 2

(x + x^-1)^2 = 2^2
x^2 + 2 . x . x^-1 + x^-2 = 4
x^2 + 2 + x^-2 = 4
x^2 + x^-2 = 2

Ingat : (a + b)^2 = a^2 + 2ab + b^2