Find H M C 76Df72
1. **Problem:** Given the function $f(q) = hq^2 + mq + c$ with gradient function $4q + 8$ and a stationary value of $-3$, find $h$, $m$, and $c$.
2. **Step 1: Understand the gradient function**
The gradient (derivative) of $f(q)$ is:
$$f'(q) = \frac{d}{dq}(hq^2 + mq + c) = 2hq + m$$
3. **Step 2: Match the given gradient function**
We know $f'(q) = 4q + 8$, so:
$$2hq + m = 4q + 8$$
Equate coefficients:
- Coefficient of $q$: $2h = 4 \Rightarrow h = 2$
- Constant term: $m = 8$
4. **Step 3: Use the stationary value condition**
A stationary point occurs where $f'(q) = 0$. Set $4q + 8 = 0$:
$$4q + 8 = 0 \Rightarrow q = -2$$
5. **Step 4: Use the stationary value $f(-2) = -3$**
Substitute $q = -2$ into $f(q)$:
$$f(-2) = h(-2)^2 + m(-2) + c = 2 \times 4 + 8 \times (-2) + c = 8 - 16 + c = -8 + c$$
Set equal to $-3$:
$$-8 + c = -3 \Rightarrow c = 5$$
6. **Final answer:**
$$h = 2, \quad m = 8, \quad c = 5$$