where . Use or for y-axis use or for x-axis This means that large close to L for to be close to , then (the distance between them) should be close to 0. For to be large, So, it is : such that
limx→∞f(x)=L where L∈R. Use ϵ or for y-axis use δ or for x-axis This means that x large ⟹ f(x) close to L for f(x) to be close to L, then ∣f−L∣<ϵ (the distance between them) should be close to 0. For x to be large, x>δ So, it is : ∀ϵ>0,∃N>0 such that x>δ⟹∣f−L∣<ϵ