1. **State the problem:**
Jerry invests 6000 at 7.5% per annum compounded annually. We want to find the instantaneous rate of change of the investment value at 10 years if the interest were compounded semi-annually instead.
2. **Formulas and explanation:**
- Compound interest formula: $$A = P\left(1 + \frac{r}{n}\right)^{nt}$$ where $P$ is principal, $r$ is annual interest rate (decimal), $n$ is number of compounding periods per year, and $t$ is time in years.
- Instantaneous rate of change is the derivative of $A$ with respect to $t$.
3. **Given values:**
- $P = 6000$
- $r = 0.075$
- $n = 2$ (semi-annual compounding)
4. **Write the function for amount $A(t)$:**
$$A(t) = 6000\left(1 + \frac{0.075}{2}\right)^{2t} = 6000\left(1.0375\right)^{2t}$$
5. **Find the derivative $A'(t)$:**
Using chain rule,
$$A'(t) = 6000 \cdot \left(1.0375\right)^{2t} \cdot \ln(1.0375) \cdot 2$$
6. **Calculate $A'(10)$:**
$$A'(10) = 6000 \cdot (1.0375)^{20} \cdot \ln(1.0375) \cdot 2$$
Calculate intermediate values:
- $(1.0375)^{20} \approx 2.030856$
- $\ln(1.0375) \approx 0.03682$
So,
$$A'(10) \approx 6000 \cdot 2.030856 \cdot 0.03682 \cdot 2 = 6000 \cdot 2.030856 \cdot 0.07364$$
$$= 6000 \cdot 0.14956 = 897.36$$
7. **Interpretation:**
The instantaneous rate of change of the investment value at 10 years with semi-annual compounding is approximately 897.36 per year.
**Final answer:**
$$\boxed{897.36}$$
Instantaneous Rate D3Edc7
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