SOLUTION: An electric circuit contains three resistors connected in parallel. If the resistance of each is R_1, R_2, ams R_3 ohms, respectively, their combined resistance R is given by the f

Question 1208650: An electric circuit contains three resistors connected in parallel. If the resistance of each is R_1, R_2, ams R_3 ohms, respectively, their combined resistance R is given by the formula

1/R = (1/R_1) + (1/R_2) + (1/R_3)

A. Express R as a rational expression.
B. Evaluate R for R_1 = 5 ohms, R_2 = 4 ohms, and R_3 = 10 ohms

Let me see.

I think for A, I need to solve for R. If so, I will use a for R_1, b for R_2, and c for R_3 for easy cell phone typing.

1/R = 1/a + 1/b + 1/c

After much effort on paper, solving for R leads me to

R = (abc)/(bc + ac + ab).

Is this correct? If so, part B is just plug and chug.

You say?
Answer by Shin123(626) (Show Source): You can put this solution on YOUR website!
Hi, for a), you did it correctly. Just make sure to plug back in R_1, R_2, and R_3 for a, b, and c in the final expression. Part b) shouldn't be too hard since you have that already.
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