Problem 3f

U(k) = (-1)^k*k

U(k+1)  = (-1)^(k+1) * (k+1)
	= (-1)^k*(-1)^1 * (k+1)		- Separate indicies
	= (-1)^k*(-1) * (k+1)
	= -(-1)^k * (k+1)
	= -(-1)^k*k + -(-1)^k
	= -U(k) - (-1)^k 		- (-1)^k*k = U(k)
	= U(k) - 2U(k) - (-1)^k		- +2U(k), -2U(k)
	= U(k) - 2(k*(-1)^k) - (-1)^k 	- Expand U(k)
	= U(k) - (2k + 1)*(-1)^k	- Collect like terms - (-1)^k

U(k+1)	= U(k) - (2k + 1)*(-1)^k