solve2
(* equazioni biquadratiche,binomie,trinomie *)
Solve[x^4-22x^2+121==0]
{{x -> 11^(1/2)}, {x -> -11^(1/2)}, {x -> 11^(1/2)}, {x -> -11^(1/2)}}
;[o]
{{x -> Sqrt[11]}, {x -> -Sqrt[11]}, {x -> Sqrt[11]}, {x -> -Sqrt[11]}}
y=3x^4-39x^2+126==0;
Solve[y]
Solve[y,x]
{{x -> 7^(1/2)}, {x -> -7^(1/2)}, {x -> 6^(1/2)}, {x -> -6^(1/2)}}
;[o]
{{x -> Sqrt[7]}, {x -> -Sqrt[7]}, {x -> Sqrt[6]}, {x -> -Sqrt[6]}}
{{x -> 7^(1/2)}, {x -> -7^(1/2)}, {x -> 6^(1/2)}, {x -> -6^(1/2)}}
;[o]
{{x -> Sqrt[7]}, {x -> -Sqrt[7]}, {x -> Sqrt[6]}, {x -> -Sqrt[6]}}
Solve[5 (x-2)^4 ==0,x]
{{x -> 2}, {x -> 2}, {x -> 2}, {x -> 2}}
;[o]
{{x -> 2}, {x -> 2}, {x -> 2}, {x -> 2}}
Solve[x^4+x^3-x^2-x==0,x]
{{x -> -1}, {x -> -1}, {x -> 0}, {x -> 1}}
;[o]
{{x -> -1}, {x -> -1}, {x -> 0}, {x -> 1}}
Solve[x^4==x^2+4x+4,x]
{{x -> -1}, {x -> 2}, {x -> (-1 + I*7^(1/2))/2}, {x -> (-1 - I*7^(1/2))/2}}
;[o]
-1 + I Sqrt[7] -1 - I Sqrt[7]
{{x -> -1}, {x -> 2}, {x -> --------------}, {x -> --------------}}
2 2
Solve[x^4-x^2-4x-4==0,x]
{{x -> -1}, {x -> 2}, {x -> (-1 + I*7^(1/2))/2}, {x -> (-1 - I*7^(1/2))/2}}
;[o]
-1 + I Sqrt[7] -1 - I Sqrt[7]
{{x -> -1}, {x -> 2}, {x -> --------------}, {x -> --------------}}
2 2
Solve[x^4-10x^2+9==0,x]
{{x -> 3}, {x -> -3}, {x -> 1}, {x -> -1}}
;[o]
{{x -> 3}, {x -> -3}, {x -> 1}, {x -> -1}}
Solve[8x^3+27==0,x]
{{x -> (3*(-1)^(1/3))/2}, {x -> -3/2}, {x -> (3*(-1)^(5/3))/2}}
;[o]
1/3 5/3
3 (-1) 3 3 (-1)
{{x -> ---------}, {x -> -(-)}, {x -> ---------}}
2 2 2