Problem 1048 (difficulty: 2/10)
Let \(\displaystyle f\) be continuous, \(\displaystyle g(x)=\begin{cases} c & \text{if $x< {a+b \over 2}$} \\ d & \text{if $x> {a+b\over 2}$} \\ e & \text{if $x={a+b\over 2}$}\end{cases}\).
\(\displaystyle \int_a^b f\ dg=?\)