; General electrical formulas:

volts=amps*ohms ; Ohm's Law, commonly solved for resistance (ohms) or current (amps).
watts=volts*amps ; Power Law
1/r=1/r1+1/r2 ; Resistance (r) of 2 resistors (r1 and r2) wired in parallel.
solve verify r ; Solve for the resulting resistance, verifying the result.
1/r=1/r1+1/r2+1/r3 ; Resistance (r) of 3 resistors wired in parallel.
solve verify r ; Solve for the resulting resistance, verifying the result.
frequency=1/(2*pi*(L*C)^.5) ; Resonant frequency of an LC circuit in hertz.
; L is the inductance in henries, and C is the capacitance in farads.