Solve Quartic with Casio FX-115MS

[Albert Chan]

(02-01-2020 12:27 PM)Albert Chan Wrote:  Unfortunately, the roots are in wrong order !

Solving (x^2 + c1 x + d1)(x^2 + c2 x + d2) = 0, gives all wrong roots.

Can anyone try the actual code, or am I mistaken somewhere ?
Source in https://thomasokken.com/free42/42progs/, named G4G

Tried above program just now, for Quartic x^4 + 2 x^3 + 3 x^2 + 4 x + 5 = 0

2 Enter 3 Enter 4 Enter 5 XEQ "G4G"

Output "X=I,Z=I" ⇒ roots = Y ± X*I, T ± Z*I ≈ -1.2878 ± -0.6555*I, 0.2878 ± -1.5204*I

Correct root should be -1.2878 ± 0.8579*I, 0.2878 ± 1.416*I

G4G code indeed gives the wrong roots