Actual Mathomatic output from the poly script
Mathomatic version 15.1.4 (www.mathomatic.org)
Copyright (C) 1987-2010 George Gesslein II.
100 equation spaces available, 1920 kilobytes per equation space.
HTML color mode enabled; disable with the -c option or "set no color".
1—> ; Combine 3 quadratic polynomial equations with 3 unknown coefficients (a, b, c).
1—> ; Solve for variables (a), (b), and (c).
1—>
1—> clear all ; restart Mathomatic
1—> ; enter all 3 equations:
1—> y1=a+b*x1+c*x1^2
#1: y1 = a + (b·x1) + (c·(x1^2))
1—> y2=a+b*x2+c*x2^2
#2: y2 = a + (b·x2) + (c·(x2^2))
2—> y3=a+b*x3+c*x3^2
#3: y3 = a + (b·x3) + (c·(x3^2))
3—> 2 ; select equation number 2 as the current equation
#2: y2 = a + (b·x2) + (c·(x2^2))
2—> eliminate a ; eliminate variable (a) from the current equation
Solving equation #1 for (a) and substituting into the current equation...
#2: y2 = (b·x2) − (x1·(b + (c·x1))) + y1 + (c·(x2^2))
2—> 3 ; select equation number 3
#3: y3 = a + (b·x3) + (c·(x3^2))
3—> eliminate a b ; eliminate variables (a) and then (b) from the current equation
Substituting the RHS of equation #1 into the current equation for variable (a)...
Solving equation #2 for (b) and substituting into the current equation...
(y1 − y2 + (c·((x2^2) − (x1^2))))·x3 (y1 − y2 + (c·((x2^2) − (x1^2))))
#3: y3 = ------------------------------------ − (x1·(--------------------------------- + (c·x1))) + y1 + (c·(x3^2))
(x1 − x2) (x1 − x2)
3—> c ; solve and find (c)
((y2·(x1 − x3)) + (y1·(x3 − x2)) − (y3·(x1 − x2)))
#3: c = -----------------------------------------------------------------
((x1·((x2^2) + (x1·(x3 − x2)))) − (x3·((x2^2) + (x3·(x1 − x2)))))
3—> simplify
(y1 − y2) (y3 − y2)
(--------- + ---------)
(x2 − x1) (x3 − x2)
#3: c = -----------------------
(x3 − x1)
3—> 2 ; select equation number 2 again
(y1 − y2 + (c·((x2^2) − (x1^2))))
#2: b = ---------------------------------
(x1 − x2)
2—> eliminate c using 3 ; find (b) by combining equation numbers 2 and 3
Substituting the RHS of equation #3 into the current equation for variable (c)...
(y1 − y2) (y3 − y2)
(--------- + ---------)·((x2^2) − (x1^2))
(x2 − x1) (x3 − x2)
(y1 − y2 + -----------------------------------------)
(x3 − x1)
#2: b = -----------------------------------------------------
(x1 − x2)
2—> simplify
(((x3^2)·(y1 − y2)) + ((x1^2)·(y2 − y3)) + ((x2^2)·(y3 − y1)))
#2: b = --------------------------------------------------------------
((x2 − x1)·(x3 − x1)·(x2 − x3))
2—> 1 ; select equation number 1
#1: a = -((x1·(b + (c·x1))) − y1)
1—> eliminate c using 3 b using 2 ; find (a)
Substituting the RHS of equation #3 into the current equation for variable (c)...
Substituting the RHS of equation #2 into the current equation for variable (b)...
(y1 − y2) (y3 − y2)
(--------- + ---------)·x1
(((x3^2)·(y1 − y2)) + ((x1^2)·(y2 − y3)) + ((x2^2)·(y3 − y1))) (x2 − x1) (x3 − x2)
#1: a = -((x1·(-------------------------------------------------------------- + --------------------------)) − y1)
((x2 − x1)·(x3 − x1)·(x2 − x3)) (x3 − x1)
1—>
1—> simplify fraction all ; list all solutions, converting to simple fractions
(((x1^2)·((y2·x3) − (y3·x2))) + (x1·(((x2^2)·y3) − ((x3^2)·y2))) + (y1·(((x3^2)·x2) − (x3·(x2^2)))))
#1: a = ----------------------------------------------------------------------------------------------------
((x2 − x1)·(x3 − x1)·(x3 − x2))
(((x3^2)·(y1 − y2)) + ((x1^2)·(y2 − y3)) + ((x2^2)·(y3 − y1)))
#2: b = --------------------------------------------------------------
((x2 − x1)·(x3 − x1)·(x2 − x3))
((x3·(y1 − y2)) + (x2·(y3 − y1)) + (x1·(y2 − y3)))
#3: c = --------------------------------------------------
((x2 − x1)·(x3 − x1)·(x3 − x2))
Finished reading file "poly.in".
1—>
End of input.
www.mathomatic.org