1. The problem is to find the values of $a$, $b$, and $k$ in the exponential function $f(x) = a b^x + k$ given the table of values:
$$\begin{array}{c|ccccc} x & 0 & 1 & 2 & 3 & 4 \\ \hline f(x) & 6 & 12 & 36 & 132 & 516 \end{array}$$
2. We start by using the value at $x=0$:
$$f(0) = a b^0 + k = a \cdot 1 + k = a + k = 6$$
This gives the equation:
$$k = 6 - a$$
3. Next, use the value at $x=1$:
$$f(1) = a b^1 + k = a b + k = 12$$
Substitute $k$ from step 2:
$$12 = a b + (6 - a) = a b + 6 - a$$
Rearranged:
$$12 - 6 = a b - a$$
$$6 = a (b - 1)$$
4. The user suggests $b = 4$ (from the arrows indicating multiplication by 4 between function values), so substitute $b=4$:
$$6 = a (4 - 1) = 3a$$
Solve for $a$:
$$a = \frac{6}{3} = 2$$
5. Substitute $a=2$ back into $k = 6 - a$:
$$k = 6 - 2 = 4$$
6. Check if this fits the next value $f(2)$:
$$f(2) = a b^2 + k = 2 \cdot 4^2 + 4 = 2 \cdot 16 + 4 = 32 + 4 = 36$$
This matches the table value.
7. Explanation why $a$ is not 6:
- At $x=0$, $f(0) = a + k = 6$, so if $a$ were 6, then $k$ would be 0.
- But using $x=1$, $f(1) = a b + k = 12$, substituting $a=6$ and $k=0$ gives $6 \cdot 4 = 24$, which does not equal 12.
- Therefore, $a$ cannot be 6; it must be 2 to satisfy both equations.
Final answer:
$$a = 2, \quad b = 4, \quad k = 4$$
Exponential Parameters Ff1280
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