若1/R1+1/R2=1/R,用R、R1表示R2,应为?

问题描述:

若1/R1+1/R2=1/R,用R、R1表示R2,应为?

1/R2=1/R-1/R1
1/R2=(R1-R)/(RR1)
R2=RR1/(R1-R)