When dividing fractions, the divisor must be inverted then multiplied with the other fraction?

Yes. That statement is true.

For example in : (1/2) divided by (3/4), you would invert 3/4 to make 4/3 and change the divide symbol to the multiply symbol. Becoming:

(1/2) multiplied by (4/3) = (1/2) divided by (3/4) = 0.66r

Using the rise/run rule. you would get 2/6.simp. 1/3