x-Intercepts and y-Intercepts of Lines

[whiskylover1973]

sorry that should be 4x-x^3

[georgewoodbury]

To find x-int's, set the function equal to 0.

Set 4x-x^3 = 0.

Now factor out a common x.

x(4-x^2)=0

Now factor as a difference of squares.

x(2+x)(2-x)=0

Set each factor equal to 0 and solve.

x=0, x=-2, x=2

[whiskylover1973]

That's great, thank you for the help :)

[whiskylover1973]

What if you were finding the x-intercepts for:

f(x)=x-x^3

?