1. **Problem statement:** We have a quadratic function $f(x) = a \cdot x^2 + b \cdot x + c$.
We know the vertex (toppunkt) is $T(2,14)$ and the tangent line at point $P(0,6)$ is $y = 8x + 6$.
We need to find the coefficients $a$, $b$, and $c$.
2. **Recall the vertex form and properties:**
The vertex $T(h,k)$ of a parabola $f(x) = a x^2 + b x + c$ satisfies:
$$h = -\frac{b}{2a}$$
$$k = f(h) = a h^2 + b h + c$$
Also, the derivative $f'(x) = 2 a x + b$ gives the slope of the tangent at any $x$.
3. **Use vertex coordinates:**
From $T(2,14)$:
$$2 = -\frac{b}{2a} \implies b = -4a$$
$$14 = a \cdot 2^2 + b \cdot 2 + c = 4a + 2b + c$$
Substitute $b = -4a$:
$$14 = 4a + 2(-4a) + c = 4a - 8a + c = -4a + c$$
So,
$$c = 14 + 4a$$
4. **Use point $P(0,6)$ on the parabola:**
At $x=0$, $f(0) = c = 6$.
From step 3, $c = 14 + 4a$, so:
$$6 = 14 + 4a \implies 4a = 6 - 14 = -8 \implies a = -2$$
5. **Find $b$ and $c$ using $a = -2$:**
$$b = -4a = -4 \times (-2) = 8$$
$$c = 14 + 4a = 14 + 4 \times (-2) = 14 - 8 = 6$$
6. **Check the slope of the tangent at $P(0,6)$:**
The derivative is:
$$f'(x) = 2 a x + b = 2 \times (-2) x + 8 = -4x + 8$$
At $x=0$:
$$f'(0) = -4 \times 0 + 8 = 8$$
This matches the slope of the tangent line $y = 8x + 6$.
**Final answer:**
$$a = -2, \quad b = 8, \quad c = 6$$
Find Abc 266Aa6
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