I'll assume this is y=-3(x-3)^2+3
to find the x-intercepts, set y=0 and solve for x:
0=-3(x-3)^2+3
-3=-3(x-3)^2
1=(x-3)^2
+/-1=x-3
+/-1 + 3 = x
x=4, x=2
this makes sense because if you look at the original equation, you see that plugging in these numbers for x, you get 0.
