You can verify that the differential equation:
−7x2y′′−14x(x−1)y′+14(x−1)y=0−7x2y″−14x(x−1)y′+14(x−1)y=0,
x>0x>0 has solutions y1=3xy1=3x and
y2=5xexp(−2x)y2=5xexp(−2x).
Compute the Wronskian WW between y1y1 and y
The solutions y1y1 and y2y2 form a fundamental set of solutions
because there is a point x0x0 where W(x0)≠0W(x0)≠0
x2 y" + (x2+x) y’
+(2x-1) y = 0,
Find the general solution of y1 with
r1 and calculate the coefficient up to
c4 and also find the general expression of the
recursion formula, (recursion formula for
y1)
Find the general solution of y2 based on
theorem 4.3.1. (Hint, set d2 = 0)
Let Y1 and Y2 have joint pdf f(y1, y2) = (6(1−y2), if 0≤y1≤y2≤1
0, otherwise. a) Are Y1 and Y2 independent? Why? b) Find Cov(Y1,
Y2). c) Find V(Y1−Y2). d) Find Var(Y1|Y2=y2).