Create slider offered, variable already defined
In the below screen dump note:
- The "b" in the INPUT field (bottom, stating "y=b x+f(x)" )
- The "b" defined in CAS window (left)
- The "b" shown in Algebra window (lower right)
- The (central) prompt to create slider for "b".
My problem is not being allowed to enter the equation (without creating b-slider).
My problem was overcome by closing down GeoGebra, restarting and opening the app once again. Now it works, but the student would not want to do this in an exam situation. Something blocked the app from accessing "b" in the first place.