Answer:
The function is
![T_(n) = 5 + 5n](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uq1jdo3ppvo5e11jef4x0m839cfuv1ywkj.png)
Explanation:
Options are missing; I'll find the function of swimmer in relation to days
Topic: Arithmetic Progression
Given
First day = 10 laps
Increment = 5 laps daily
To get the function of the number of days, we make use of the arithmetic progression formula.
![T_(n) = a + (n - 1) d](https://img.qammunity.org/2020/formulas/mathematics/middle-school/l3xxwr37jcc70zsn3hnrs9ef9bji9fjpio.png)
Where a = first term = 10 laps
n = number of days
d = common difference = 5
![T_(n) = The Function](https://img.qammunity.org/2020/formulas/mathematics/middle-school/doa41u23vaa2cm20pb685g9kbma3l295qz.png)
By Substitution
![T_(n) = a + (n - 1) d ---- Substitute\\ T_(n) = 10 + (n - 1) 5 \\T_(n) = 10 + 5n - 5\\T_(n) = 10 - 5 + 5n \\T_(n) = 5 + 5n \\](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qzbdaqea3cmzkp4gmfkg9i29pdjit4tmwg.png)
Hence, the function is
![T_(n) = 5 + 5n](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uq1jdo3ppvo5e11jef4x0m839cfuv1ywkj.png)
where n = number of days