How to do$?$ with explanation pls$.$ thanks

Assume you have a cell with two dendrites. In this case, the radius of dendrite $A$ is $1\mathrm{.}5$

$m$ and its length is $50m.$ The radius of dendrite B is $2m$ and its length is $200m.$

You have successfully attached a micropipette electrode to the very end of each of the

dendrites. The resting membrane potential of the cell is $-75mV.$

$R_m=1500*c{m}^2$

$R_i=300*cm$

$C_m=1\frac{F}{c}{m}^2$

A$)$ Into dendrite A$,$ you inject a hyperpolarizing current which hyperpolarizes

the end of the dendrite by $30mV.$ Assuming that the dendrite can be modeled as

an infinitely long cable, what is the voltage at the end of the dendrite where it

meets the soma? For this problem, ignore the effect of the soma on the voltage.

B$)$ Similarly, you inject a depolarizing current into dendrite B which depolarizes

the end of the dendrite by $50mV.$ Assuming that the dendrite can be modeled as

an infinitely long cable, what is the voltage at the end of the dendrite where it

meets the soma? For this problem, ignore the effect of the soma on the voltage.

C$)$ If the resistance between dendrite A and the soma is $90M,$ what is the

current that flows into the cell body from dendrite A$?$

D$)$ If the resistance between dendrite $B$ and the soma is $25M,$ what is the

current that flows into the cell body from dendrite B$?$

E$)$ If the threshold potential for the soma is $-50mV$ and the two currents are

applied to the dendrites for $5$msec, will the cell fire an action potential? Assume

that the cell is a perfect sphere with a radius of $20m$ and that the same

parameters for the dendrite membrane above apply to the plasma membrane:

F$)$ If the depolarizing stimulus was applied to dendrite B$,$ but no stimulus was

applied to dendrite A$,$ would the cell fire an action potential? Use the same

parameters for the cell as in $4E.$

G$)$ Assume that the cell from the previous question fired an action potential, and

that it was traveling down a myelinated axon. As a result of your experimental

preparation, you've damaged the axon and removed some of the myelin sheath.

Given the following parameters for the axon, how long of a segment of the axon

could be demyelinated before the axon membrane voltage drops below the

threshold voltage? Assume that the ion channels are located at the ends of the

unmyelinated region only and that the steady state solution of the cable equation

applies. The peak voltage of the action potential is $+30mV$ the threshold

potential is $-40mV,$ and the resting membrane potential is $-75mV.$