1.7.2 Types of sequence (A-level only)

A sequence $u_1, u_2, u_3, \dots\,$ is defined by

\begin{aligned}u_1 &= 3 \\u_{n+1} &= u_n + c, \quad n \geq 1\end{aligned}

Given $u_5 = 21$

a.

Find the value of $c$ .

[3]

b.

Find an expression for $u_n\,$ in terms of $n$ .

[2]

A sequence $u_1, u_2, u_3, \dots\,$ is defined by

\begin{aligned}u_1 &= 3 \\u_{n+1} &= u_n + c, \quad n \geq 1\end{aligned}

Given $u_5 = 21$

a.

Find the value of $c$ .

[3]

b.

Find an expression for $u_n\,$ in terms of $n$ .

[2]

1.7.2 Types of sequence (A-level only) Questions