2. Let X₁ and X₂ be jointly continuous random variables with probability density function:
fX1,X2 (X1, X2). Let Y₁ = X1 + X2 and Y2 = X1 - X2,
a. Find the joint density function fr₁,Y₂ (У1, Уг),
b. If X₁ and X2 are independent and uniform in the interval [0,1] random variables,
find the joint pdfs of fx1,x2 (x1, x2), and fr₁₂ (Y1, Y2)