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1/s+1/i=1/f, need i = ...

BearishSun

New member
Joined
Jan 8, 2010
Messages
2
Hello,

how do I get equation "1/s+1/i=1/f" in the form i = ... ?

The solution is i = f*s/(s-f), but I'd like to know the steps for getting the solution.

Thanks in advance
 

galactus

Super Moderator
Staff member
Joined
Sep 28, 2005
Messages
7,216
Find your LCD. It is \(\displaystyle sif\), isn't it?.

\(\displaystyle \frac{if}{if}\cdot\frac{1}{s}+\frac{sf}{sf}\cdot\frac{1}{i}=\frac{si}{si}\cdot\frac{1}{f}\)

Now that the denominators are the same, concentrate on the numerators.

\(\displaystyle if+sf=si\)

Now, solve for i.
 

BearishSun

New member
Joined
Jan 8, 2010
Messages
2
So simple...still, I doubt it would occur to me

Thanks again
 

Subhotosh Khan

Super Moderator
Staff member
Joined
Jun 18, 2007
Messages
18,091
Too many ifs in the problem .... :D :D :mrgreen:
 
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