# Bug in command "Factors"

Robert T. shared this problem 1 year ago
Solved

While programming an applet for polynomial functions and comparing factors and multiplicites I stumbled over a strange behaviour of the Factors command in Geogebra classic 5. It can simply be reproduced:

Type the following commands:

f(x)=x^2-1

a=Factors(f)

Result is correct: a is shown as { {x-1,1}, {x+1,1} }

Now change f(x) to f(x)=0 by typing f(x)=0.

Result is confusing: a is now shown as { {x-1,1}, {x+1,1}, {0,1} }

Type f(x)=0 again:

Result is growing: a is now shown as { {x-1,1}, {x+1,1}, {0,1}, {0,1} }

The factors list can be resetted by using any other definition of f(x) unequal to zero. That's my suggestion for a work-around.

A little confusing is the result for f(x) = 1:

The factors list is shown as {{0,0}} which of course is unique and can be interpreted as 1, but I have a doubt that it's intuitive for pupils. 1

Thanks, we'll check! 1

Fixed for next release (v504) 1

Looks good! Thank you! 