# Functions not showing very well

RobertoCSa shared this question 7 years ago

I´ve noticed two problems with functions:

1) f(x)=abs(x)/x // does not show the function´s open point in x=0.

2) se[x<-2 && x>2, x^2, 0] //Shows only the false part (f(x)=0)

1

Already discovered problem with item 2: It was my fault. I have changed the signals (steady of && it should be ||).

1

1) f(x)=abs(x)/x // does not show the function´s open point in x=0.

That's expected

1

Murkle, could you, please, explain why, in mathematical terms, the Geogebra is considering to exist a possible result in the function abs(x)/x for x=0? The program does not assume the function is working with reals numbers?

1

Already discovered problem with item 2: It was my fault. I have changed the signals (steady of && it should be ||).

1

Murkle, could you, please, explain why, in mathematical terms, the Geogebra is considering to exist a possible result in the function abs(x)/x for x=0?

f(x)=abs(x)/x

f(0)

gives undefined. GeoGebra just doesn't make any attempt to show this graphically.