What is the equivalent resistance of two resistors of 2 ohm and 3 ohm connected in parallel?

Answer 1

1/R = 1/R1 + 1/R2 = (R1 + R2)/R1 R2
so
R = R1 R2 / (R1+R2)

= 6/5 = 1.2 Ohms

to derive
i1 = V/R1
I2 = V/R2

i = i1+i2 = V/R1 + V/R2
but
R = V/i = V/(V/R1 +V/R2) = 1/(1/R1+1/R2)
= R1 R2 / (R2 + R1)