PKPKBHmimetypetext/x-wxmathmlPKPK8^ content.xml Kelvinov most, izvodjenje potenciometarski razdelnik vb: R2 / (R1 + R2) * E; (%o1) E*R2R2+R1 razdelnik na strani nepoznatog otpornika va: v2 + R2 / (R1 + R2) * (v1 - v2); (%o2)

v1v2

*R2
R2+R1
+v2
va: ratsimp(va); (%o3) v2*R1+v1*R2R2+R1 da nadjemo v1 i v2 v2: R4 / (R4 + Rz + R3) * E; (%o4) E*R4R4+R3+Rz v1: (R4 + Rz) / (R4 + Rz + R3) * E; (%o5) E*

Rz+R4

R4+R3+Rz
da sredimo izraze, prljav posao za wxMaxima va; (%o6) v2*R1+v1*R2R2+R1 va: ev(va); (%o7) E*R1*R4R4+R3+Rz+E*R2*

Rz+R4

R4+R3+Rz
R2+R1
va: ratsimp(va); (%o8) Rz*E*R2+

E*R2+E*R1

*R4

R1+R2

*R4+

R1+R2

*R3+Rz*R2+Rz*R1
va: factor(va); (%o9) E*

Rz*R2+R1*R4+R2*R4

R2+R1

*

R4+R3+Rz

ravnoteza mosta e: va - vb; (%o10) E*

Rz*R2+R1*R4+R2*R4

R2+R1

*

R4+R3+Rz

E*R2R2+R1
e: ratsimp(e); (%o11) E*R1*R4E*R2*R3

R1+R2

*R4+

R1+R2

*R3+Rz*R2+Rz*R1
e: factor(e); (%o12) E*

R1*R4R2*R3

R2+R1

*

R4+R3+Rz

imenilac me ne zanima, hocu nulu brojioca ne: num(e); (%o13) E*

R1*R4R2*R3

i da resimo Rx: solve(ne, R4); (%o14) [R4=R2*R3R1] to je sve, lakse nego rukom na tabli!
PKPKBHmimetypePKPK8^ 5content.xmlPKo