+983
\(\text{midline}=\frac{\text{max value}+\text{min value}}{2}\)
Since the amplitude of a sinusoid is equal to the vertical distance from its midline to one of its extrema, we can also calculate the midline using one of the following formulas.
\(\text{midline}=\text{max value}-\text{amplitude}\)
\(\text{midline}=\text{min value}+\text{amplitude}\)
I'm going to leave the calculating to you.
I hope this helped,
Gavin
