fg

Could you clarify what you mean by "fg"? It could refer to a few different things. Here are the two most common in math:

• Function composition: (f ∘ g)(x) = f(g(x)) Example: f(x) = x^2, g(x) = x + 1 => (f ∘ g)(x) = (x + 1)^2 Derivative rule: (f ∘ g)'(x) = f'(g(x)) · g'(x)

• Product of functions: (f · g)(x) = f(x) · g(x) Example: f(x) = x, g(x) = x^2 => (f · g)(x) = x^3 Derivative rule: (f · g)'(x) = f'(x) · g(x) + f(x) · g'(x)

If you meant something else (e.g., a topic in a specific course, like Fourier transforms F{g}, or a physics/CS concept), tell me.

If you’d like, I can give a quick drill (5–10 questions) on function composition and/or product rules, with solutions. Also tell me your course level and the topic you’re studying.