MHB Odd Arrangement - Isolate the term "Ru" in V/(Vin*R)=(1/(R+Ru*k))-(1/(R+Ru))

[Outdoors]

I thought my algebra skills were good, but this problem has me frustrated. I would like to rearrange the equation to solve for Ru, but I can't seem to get Ru isolated. All values are known except for Ru.

V/(Vin*R)=(1/(R+Ru*k))-(1/(R+Ru))Thank you in advance.

 

[tkhunny]

Re: Odd Arrangement - Isolate Ru

Well, what did you do first? You'll have to get Ru out of the denominators.

Two different denominators? I'm guessing you'll need your Quadratic Formula. Can you figure out which solution will be acceptable?

 

[Joppy]

Re: Odd Arrangement - Isolate Ru

Welcome to MHB!

Hint: I would try grouping the RHS into a single fraction (find a common denominator), and then 'crank the handle'. i.e. multiply and group terms, you should end up with a quadratic in $R_{\rm u}$.

Edit: whoops, tkhunny beat me to it!

 

[Outdoors]

Re: Odd Arrangement - Isolate Ru

Well, what did you do first? You'll have to get Ru out of the denominators.

Two different denominators? I'm guessing you'll need your Quadratic Formula. Can you figure out which solution will be acceptable?

While you were able to see it more quickly, I've finally come to the same conclusion. I was able to put the equation in a quadratic form, equal to zero. Thank you for your help.

- - - Updated - - -

Welcome to MHB!

Hint: I would try grouping the RHS into a single fraction (find a common denominator), and then 'crank the handle'. i.e. multiply and group terms, you should end up with a quadratic in $R_{\rm u}$.

Edit: whoops, tkhunny beat me to it!

While you were able to see it more quickly, I've finally come to the same conclusion. I was able to put the equation in a quadratic form, equal to zero. Thank you for your help.

 

[tkhunny]

Re: Odd Arrangement - Isolate Ru

While you were able to see it more quickly, I've finally come to the same conclusion. I was able to put the equation in a quadratic form, equal to zero. Thank you for your help.

Good work! Was it messier than you expected?

 

[Outdoors]

Re: Odd Arrangement - Isolate Ru

Good work! Was it messier than you expected?

All the previous approaches were messy. The approach that led to the quadratic form was clean. It all took way too long though. Rusty I guess.

 

[tkhunny]

Re: Odd Arrangement - Isolate Ru

All the previous approaches were messy. The approach that led to the quadratic form was clean. It all took way too long though. Rusty I guess.

Perfect. Hang in there. You're getting back up to speed already!