tmua 2017 Q15

tmua · Uk · paper2 1 marks Sequences and series, recurrence and convergence
The function $f$ is defined on the positive integers as follows:
$$f ( 1 ) = 5 , \text { and for } n \geqslant 1 : \quad \begin{array} { l l } f ( n + 1 ) = 3 f ( n ) + 1 & \text { if } f ( n ) \text { is odd } \\ & f ( n + 1 ) = \frac { 1 } { 2 } f ( n ) \end{array} \text { if } f ( n ) \text { is even }$$
The function $g$ is defined on the positive integers as follows:
$$\begin{array} { l l } g ( 1 ) = 3 , \text { and for } n \geqslant 1 : \quad & g ( n + 1 ) = g ( n ) + 5 \\ & \text { if } g ( n ) \text { is odd } \\ g ( n + 1 ) = \frac { 1 } { 2 } g ( n ) & \text { if } g ( n ) \text { is even } \end{array}$$
What is the value of $f ( 1000 ) - g ( 1000 )$ ?
A - 6
B - 5
C 1
D 2
E 4
F 8
& B
The function $f$ is defined on the positive integers as follows:

$$f ( 1 ) = 5 , \text { and for } n \geqslant 1 : \quad \begin{array} { l l } 
f ( n + 1 ) = 3 f ( n ) + 1 & \text { if } f ( n ) \text { is odd } \\
& f ( n + 1 ) = \frac { 1 } { 2 } f ( n )
\end{array} \text { if } f ( n ) \text { is even }$$

The function $g$ is defined on the positive integers as follows:

$$\begin{array} { l l } 
g ( 1 ) = 3 , \text { and for } n \geqslant 1 : \quad & g ( n + 1 ) = g ( n ) + 5 \\
& \text { if } g ( n ) \text { is odd } \\
g ( n + 1 ) = \frac { 1 } { 2 } g ( n ) & \text { if } g ( n ) \text { is even }
\end{array}$$

What is the value of $f ( 1000 ) - g ( 1000 )$ ?

A - 6

B - 5

C 1

D 2

E 4

F 8