Answer:

Step-by-step explanation:
The PDF of X is
The PDF of Y is
The means of X and Y are respectively,
so we can see that the larger the parameter, the smaller the mean. Hence the PDF of Z = min(X, Y) is an exponential with the largest parameter of the two.
Therefore, the PDF of Z is
<span> A. x²+2 - a polynomial
B.(x⁸-2)/(x⁻²+3) rational function
C. 7x⁷-2x⁻⁴+3 (It has negative value of exponent, so it cannot be a polynomial.)
D.x^x-1 (x is an exponent it cannot be a polynomial)</span>