Help with intro circuit analysis problem Thevenin and max power prob

[nchin]

No, you'll get an expression for I3 in terms of R_L and I_o. That expression will allow you to pick out the Thevenin voltage and resistance. With the Thevenin resistance you known the value of R_L that will maximize the power delivered to R_L.

When we solve for i3 we will have two unknown variables in it right? Rl and Io

 

[gneill]

When we solve for i3 we will have two unknown variables in it right? Rl and Io

Yes. But we have the advantage of knowing something about RL and its relationship to Rth for maximum power transfer, regardless of the value of Io. As I stated previously, we can pick out Rth and Vth from the result of finding the expression for i3*RL.