Jointly continuous PDF ·Definition Two random variables X and Y are jointly continuous if there is a function fx,y(x,y)on R-,called the joint probability density function,such that PX≤s,Y≤t)= fx.y(x,y)dxdy x≤S,Jy≤t 4Jointly continuous PDF • Definition Two random variables 𝑋 and 𝑌 are jointly continuous if there is a function 𝑓𝑋,𝑌 𝑥, 𝑦 on 𝑅 2 , called the joint probability density function, such that 𝑃 𝑋 ≤ 𝑠, 𝑌 ≤ 𝑡 = 𝑓𝑋,𝑌 𝑥, 𝑦 𝑑𝑥𝑑𝑦 𝑥≤𝑠,𝑦≤𝑡 4