show or explain all work please.....
2007-08-25 14:46:36 · 3 answers · asked by XoXoMiSsTwInKlEsXoXo 1 in Science & Mathematics ➔ Mathematics
R (r1) + R (r2) = r1 r2
R (r2) - r1 r2 = - R (r1)
r2 (R - r1) = - R (r1)
r2 = - R (r1) / (R - r1)
r2 = R (r1) / (r1 - R) (ohms!!)
2007-08-25 21:22:44 · answer #1 · answered by Como 7 · 1⤊ 0⤋
R(r1 + r2) = r1r2
Expand the left hand side of the equation......
Rr1 + Rr2 = r1r2
Bring the terms with r2 to the right hand side of the equation......
Rr1 = r1r2 - Rr2
Factorise the right hand side of the equation......
Rr1 = r2(r1 - R)
Bring the term (r1 - R) to the left hand side......
Rr1/(r1 - R) = r2
Therefore, r2 = Rr1/(r1 - R).
NOTE: You would not be able to solve for r2 unless the values of R and r1 are given. You would only be able to change the subject of this equation to r2.
2007-08-25 15:22:53 · answer #2 · answered by Anonymous · 0⤊ 0⤋
first open the brackets
Rr1 +Rr2= r1r2
since u need to solve for r2 taka them on lhs
Rr2 -r1r2 = -Rr1
take r2 common
r2(R -r1) = -Rr1
r2 = -Rr1/(R -r1)
2007-08-25 14:58:03 · answer #3 · answered by mubaris h 3 · 0⤊ 0⤋