Inverse Cosine Domain Range E29Cc2
1. **Problem:** Sketch the function $$f(x) = 2 \cos^{-1}(-x + 1) + 1$$ and find its domain and range.
2. **Recall the inverse cosine function properties:**
- The function $$\cos^{-1}(z)$$ is defined for $$z \in [-1,1]$$.
- Its range is $$[0, \pi]$$.
3. **Find the domain of $$f(x)$$:**
Since $$f(x)$$ involves $$\cos^{-1}(-x + 1)$$, the argument must satisfy:
$$-1 \leq -x + 1 \leq 1$$
4. **Solve inequalities for $$x$$:**
- From $$-1 \leq -x + 1$$:
$$-1 \leq -x + 1 \implies -2 \leq -x \implies x \leq 2$$
- From $$-x + 1 \leq 1$$:
$$-x + 1 \leq 1 \implies -x \leq 0 \implies x \geq 0$$
5. **Domain:**
$$0 \leq x \leq 2$$
6. **Find the range of $$f(x)$$:**
- Since $$\cos^{-1}(z) \in [0, \pi]$$, then:
$$2 \cos^{-1}(-x + 1) \in [0, 2\pi]$$
- Adding 1 shifts the range:
$$f(x) = 2 \cos^{-1}(-x + 1) + 1 \in [1, 2\pi + 1]$$
7. **Summary:**
- Domain: $$[0, 2]$$
- Range: $$[1, 2\pi + 1]$$
8. **Graph behavior:**
- At $$x=0$$, $$f(0) = 2 \cos^{-1}(1) + 1 = 2 \cdot 0 + 1 = 1$$
- At $$x=2$$, $$f(2) = 2 \cos^{-1}(-1) + 1 = 2 \pi + 1$$
This confirms the range.