examday

Community mocks

Daniel J Smith Custom TMUA Set A Paper 1 · Q15

Paper 1Sequences & series

A sequence (un)(u_n) is defined by u1>0u_1>0 and

un+1=un1+unu_{n+1}=\frac{u_n}{1+u_n}

for all integers n≥1n\geq1

Which of the following is equal to ∑n=1∞un\sum_{n=1}^{\infty}u_n?

Au1u_1
Bu11−u1\frac{u_1}{1-u_1}
C1u1\frac1{u_1}
D1+u11+u_1
E11+u1\frac1{1+u_1}
FThe series does not converge for any u1>0u_1>0

Read the questions freely. Sign in to check your answer, see the worked solution and save your progress.

Sign in to check your answerPractise the whole paper →