# Question Video: Identifying Functions Mathematics • Second Year of Secondary School

Which of the following is the equation 𝑦³ = 𝑥² + 1 expressed in function notation? [A] 𝑓(𝑥) = 𝑥² + 1 [B] 𝑓(𝑥) = (𝑥² + 1)³ [C] This cannot be expressed as a function. [D] 𝑓(𝑥) = ∛(𝑥² + 1) [E] 𝑓(𝑦) = 𝑥² + 1