Answer:
![V_(I)=-11812.39](https://img.qammunity.org/2021/formulas/business/college/59s483ga6ll29tkxrez9uotvftkrt12r6a.png)
![V_(R)=-810.81](https://img.qammunity.org/2021/formulas/business/college/6z0arodg2f4fmuub5vp5bzad2f60r6su1s.png)
Step-by-step explanation:
We will first state the equation.
![V(I,R)=1000[(1+0.07(1-R))/(1+I)]^(10)](https://img.qammunity.org/2021/formulas/business/college/9hj821cajrsvhf7fyx705dbzffj20gtp71.png)
Where:
I = annual rate of inflation;
R = the tax rate for the person making the investment.
We first determine the partial derivatives with respect to I and R.
![(dV)/(dI)=-10000((1+0.07(1-R))^(10))/((1+I)^(11))](https://img.qammunity.org/2021/formulas/business/college/d4zvgiuo5tgaq0kcdz5069pzl2j5tugg76.png)
![(dV)/(dR)=-700((1+0.07(1-R))^(9))/((1+I)^(10))](https://img.qammunity.org/2021/formulas/business/college/9ncd9qlmczzrxu82ne9ey72x9ho91p4v61.png)
VI(0.03, 0.28)
![(dV(0.03,0.28)/(dI)=-10000((1+0.07(1-0.28))^(10))/((1+0.03)^(11))](https://img.qammunity.org/2021/formulas/business/college/1ixcwbc2p3x6azd6h431qkplqr8wqc3kp2.png)
=-11812.39
![(dV(0.03,0.28))/(dR)=-700((1+0.07(1-0.28))^(9))/((1+0.03)^(10))](https://img.qammunity.org/2021/formulas/business/college/3ml7gl90wblz3ysbx0gz12v8teycp1jcth.png)
=-810.81