Question

If g (x)= x^2-5, where does the graph g (x) cross the x-axis?

Answer 1

The graph crosses the x axis  where  g(x) = 0 , so:-

x^2 - 5 = 0
x^2 = 5
x =  sqrt5 or -sqrt5

so grapg corosses the x axis at (-sqrt5,0) and (sqrt5, 0)