Properties
Category
English
Similar Topics
Statistics
Comments
2
Participants
2
Subscribers
2
Votes
1
Views
352
Share
Sine function root points "undefined"?
Answered
Hi, when I enter a sine function like f(x)=3sin(x) i can use root command to find the root points.
But when I enter a range like f(x)=3sin(x), 0<=x<=4 then root returns "undefined".
What am I doing wrong?
Files:
root in sine fu...
 GeoGebra
 Help
 Partners

Contact us
 Feedback & Questions
 This email address is being protected from spambots. You need JavaScript enabled to view it.
 +43 677 6137 2693
© 2020 International GeoGebra Institute
Salut Stefan,
the reason is that the root(s)command in this form only works for polynomials.
Look here: https://wiki.geogebra.org/en/Root_Command and https://wiki.geogebra.org/e...
So you have to add a startvalue.
You can see in the attached file the effects of the restriction of the domain of the sine function by finding roots.
I know that this is mindboggling, because you are expecting, that GeoGebra should "know" the roots like you do.
But indeed, sometimes GeoGebra is dumb as a rock.
Greetings
mire2
Thank you for your help with this, effectively I didn't know that limitation. It is peculiar, I thought geogebra calculates the roots even if I limit the scope to a certain range.
For those interested, if you use the menu a lot and select "crossing with object" from the menu twice (once per root point!) it will calculate the root points in my example just fine. What is even more odd is that Geogebra doesn't find the second root at first try. You have to click twice (or use the root function like Mire2 stated).
You just cannot select "root" from the menu for a function with limited scope like my example.
Comments have been locked on this page!