Answer
$\text{See explanation.}$
Work Step by Step
$\text{According to the Theorem of Pythagoras, the length of the segment is}$
\begin{align}
L = \sqrt {1 + 5^2} =\sqrt {26}
\end{align}
$\text{(a) Formula (4)}$
\begin{align}
L = \int_0^1 \sqrt {1+5^2} \ dx = \sqrt {26}
\end{align}
$\text{(b) Formula (5)}$
\begin{align}
L = \int_0^5 \sqrt {1+\frac{1}{25}} \ dy = \sqrt {26}
\end{align}
$\text{Thus, we have confirmed that the results are correct.}$
