1. **State the problem:** We are given the function $$f(x) = \frac{1}{2} \cdot 4^x + 3$$ and asked to find the value of its inverse function $$f^{-1}$$ at $$x = 5$$.
2. **Recall the definition of inverse function:** The inverse function $$f^{-1}(y)$$ gives the value of $$x$$ such that $$f(x) = y$$.
3. **Set up the equation:** To find $$f^{-1}(5)$$, solve for $$x$$ in the equation:
$$
5 = \frac{1}{2} \cdot 4^x + 3
$$
4. **Isolate the exponential term:**
$$
5 - 3 = \frac{1}{2} \cdot 4^x
$$
$$
2 = \frac{1}{2} \cdot 4^x
$$
5. **Multiply both sides by 2 to clear the fraction:**
$$
2 \times 2 = \cancel{2} \times \frac{1}{\cancel{2}} \cdot 4^x
$$
$$
4 = 4^x
$$
6. **Rewrite 4 as a power of 4:**
$$
4 = 4^1
$$
7. **Since bases are equal, set exponents equal:**
$$
x = 1
$$
8. **Conclusion:**
$$f^{-1}(5) = 1$$
**Answer:** Option C. 1
Inverse Function Value Ac5978
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