To find your x-intercepts, set f(x)=0, so 0=x^6-63x^3-64. You can do this by factoring x^6-63x^3-64 into [tex](x^3-64)(x^3+1)[/tex], giving you [tex](x^3-64)(x^3+1)=0[/tex]. Next, solve each factor for x if f(x)=0, so [tex](x^3-64)=0[/tex] and [tex](x^3+1)=0[/tex]. Solving for x gives you [tex]x= \sqrt[3]{64} =4[/tex] and [tex]x= \sqrt[3]{-1}=-1 [/tex], meaning your x-intercepts are (4,0) and (-1,0)