Answer
bk = 1/(k+1)
Work Step by Step
bk = bk-1/(1+bk-1), for all integers k ≥ 1, b0 = 1
b1 = b0/(1+b0) = 1/(1+1) = 1/2
b2 = b1/(1+b1) = (1/2)/(1+(1/2)) = 1/2/(3/2) = 1/2 * 2/3 = 1/3
b3 = b2/(1+b2) = (1/3)/(1+(1/3)) = 1/3/(4/3) = 1/3 * 3/4 = 1/4
b4 = b3/(1+b3) = 1/4/(1+(1/4)) = 1/4/(5/4) = 1/4*4/5 = 1/5
bk = 1/(k+1)