+261 If 23=x^4+1/(x^4), then what is the value of x^2+1/(x^2)?
where do i even start? :'(
+36916 Sum of squares factorization:
A² + B² = (A+B)² − 2AB
A = x^2
B = 1/x^2
(x^2 + 1/x^2)^2 - 2 x^2(1/x^2) = (x^2 + 1/x^2)^2 -2 = 23
(x^2 + 1/x^2)^2 = 25
x^2+ 1/x^2 = 5 (taking the positive root)
