Revise-Joint PDF Two continuous random variables X,Y satisfying P(xY)∈B)=∬kv(x,y)dxdy X,y)∈B for every subset BRevise - Joint PDF  Two continuous random variables 𝑋, 𝑌 satisfying 𝑃 𝑋, 𝑌 ∈ 𝐵 = ඵ (𝑥,𝑦)∈𝐵 𝑓𝑋,𝑌 𝑥, 𝑦 𝑑𝑥𝑑𝑦 for every subset 𝐵