TI83 Trinomial Factor Program






This program runs on a TI83 or higher. It factors second degree trinomials with integer coefficients if they can be factored with integers. It is different from a number of TI programs I have seen in that it first pulls out a common factor to the three coefficients and then factors what remains. It is based on the quadratic equation and is short and sweet. It is within reason to type it by hand into your calculator.



This program, called QFACT, was written 4/15/10 by James T. Parker and is declared to be public domain. Note that ^2 refers to the "x squared" button and SQRT refers to the "2nd x squared" button.

:ClrHome
:Disp "FACTOR AX^2+BX+C"
:Disp "A,B,C = INTEGERS"
:Disp "A IS NOT ZERO"
:Prompt A,B,C
:B^2-4AC->D
:If D<0
:Then
:Disp "INVALID"
:Stop
:End
:If fPart(SQRT(D))>0
:Then
:Disp "INVALID"
:Stop
:End
:abs(A)/A->S
:Disp "K(AX+B)(CX+D)"
:Disp S*gcd(SA,gcd(abs(B),abs(C)))
:SB+SQRT(D)->E
:SB-SQRT(D)->F
:gcd(2SA,abs(E))->C
:Disp 2SA/C
:Disp E/C
:gcd(2SA,abs(F))->C
:Disp 2SA/C
:Disp F/C



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