Question

How do you find `w(x+1)` given `w(x)=x^3-2x`?

Answer 1

You just sub in `x+1` wherever `x` is.

`w(x+1)=(x+1)^3-2(x+1)`

Explanation:

You have:
`w(x)=x^3-2x`

If you wanted to find `w(u)`, all you need to do is sub in `u` wherever `x` is.

So `w(u)=u^3-2u`

Similarly, if you wanted to find `w(x+1)`, you just sub in `x+1` wherever `x` is.

So `w(x+1)=(x+1)^3-2(x+1)`

If the question also wants you to then expand and simplify this, you could expand the expression `(x+1)^3-2(x+1)`, and then add/subtract common terms.