Cosine Vertical Shift
1. **Problem Statement:**
We are given a cosine graph that has been vertically shifted. The general form of the function is $$y = \cos(x) + C$$ where $$C$$ is the vertical shift.
2. **Understanding the cosine function:**
The basic cosine function $$y = \cos(x)$$ oscillates between -1 and 1 with a midline at $$y=0$$.
3. **Vertical shift:**
If the graph is shifted vertically by $$C$$ units, the midline moves from $$y=0$$ to $$y=C$$.
4. **Analyzing the graph:**
From the description, the wave ranges approximately from -6 to 5.
5. **Calculate the vertical shift:**
The amplitude of cosine is 1, so the range of $$y=\cos(x)$$ is $$[-1,1]$$.
If the graph is shifted by $$C$$, the new range is $$[C-1, C+1]$$.
Given the range is approximately $$[-6,5]$$, we set:
$$C - 1 = -6$$ and $$C + 1 = 5$$
6. **Solve for $$C$$:**
From $$C - 1 = -6$$, we get $$C = -5$$.
From $$C + 1 = 5$$, we get $$C = 4$$.
These two values contradict, so we re-examine the range.
7. **Re-examining the range:**
The range from -6 to 5 is asymmetric, which is unusual for a cosine function with a vertical shift only.
Assuming the graph's midline is at the average of the max and min:
$$C = \frac{-6 + 5}{2} = \frac{-1}{2} = -0.5$$
8. **Check amplitude:**
Amplitude $$A = \frac{5 - (-6)}{2} = \frac{11}{2} = 5.5$$
Since the amplitude is not 1, the function is actually:
$$y = 5.5 \cos(x) - 0.5$$
9. **Final equation:**
The vertical shift is $$-0.5$$.
**Answer:** $$y = 5.5 \cos(x) - 0.5$$