Trig/Math problem, If two resistors with resistances R1 and R2 are connected in parallel..

If two resistors with resistances R1 and R2 are connected in parallel, then the total resistance R is given by R = 1/((1/R1)+(1/R2)) . Find the total resistance of a 5 ohm resistor and a 3 ohm resistor that are connected in parallel

Answer in units of ohm

Product over sum: R = 5*3/[5 + 3] = 15/8 = 1.875 Ω

This is NOT Trig/Math matter.

Just plug R1 = 5 & R2 = 3, & get R