[tex]f(x) = (x^2 - 9)(x +1) [/tex]
when f(x) = 0,
[tex](x^2 - 9)(x +1) = 0[/tex]
[tex] (x - 3)(x+3)(x +1) = 0[/tex]
[tex] (x - 3) = 0 \text { or } (x+3)= 0 \text { or } (x +1) = 0 [/tex]
[tex]x = 3 \text { or } x= -3 \text { or } x= -1 [/tex]
The graph cuts the y-axis at (3, 0), (-3, 0) and (-1, 0)
