You can either use CAS, or Algebra View and Graphics View together, to find where the graph of a function intersects the coordinate axes. The instructions for both methods are detailed below. 
     GeoGebra Instruction 1
CAS CAS     under         View     in         Menu.         f(x):=       and         press         Enter.         f(x)=0     and         click         Solve Solve     Numerically f(0)     and         press         Symbolic     Evaluation Numeric     Evaluation 
      
     GeoGebra Instruction 2
Graphics View Algebra     View     and         Graphics     View     under         View     in         Menu.         Algebra     View     and         press         Enter.         Toolbar,         select         Intersect Point The         intersection         points         between         the         graph         and         the         axes         are         displayed         in         Algebra     View.