eliminating I1(s)

[PG1995]

Hi

Could you please help me with this query? Thanks.

Regards
PG

 

[MrAl]

Hi,

I am surprised no one answered this yet.

Solve equ 3-70 for I1(s), then insert that solution into equ 3-69, call that new equation A1 and it only has I2(s) in it now. Then solve equ 3-71 for I2(s), then insert that into the new equation A1, solving for Eo/Ei.

So the whole deal here is to solve for I1 and I2 simultaneously.

 

[steveB]

PG,

There are many methods. For example, you can use the elimination method. The basic idea is explained here.

https://www.mathplanet.com/educatio...elimination-method-for-solving-linear-systems

It amounts to multiplying one equation by an appropriate parameter (that does not include the variables), and then adding two equations to create a new equation.

In this example, you can either multiply eqn. 3-70 by (1 + R1 C1 s), then add this new equation to 3-69. Or, divide eqn. 3.69 by (1 + R1 C1 s), then add the new equation to 3-70.